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Sample records for endogenous cannabinoid receptor

  1. Cannabinoid receptors and their endogenous agonist, anandamide.

    PubMed

    Axelrod, J; Felder, C C

    1998-05-01

    Cannabinoids are a class of compound found in marijuana which have been known for their therapeutic and psychoactive properties for at least 4000 years. Isolation of the active principle in marijuana, delta9-THC, provided the lead structure in the development of highly potent congeners which were used to probe for the mechanism of marijuana action. Cannabinoids were shown to bind to selective binding sites in brain tissue thereby regulating second messenger formation. Such studies led to the cloning of three cannabinoid receptor subtypes, CB1, CB2, and CB1A all of which belong to the superfamily of G protein-coupled plasma membrane receptors. Analogous to the discovery of endogenous opiates, isolation of cannabinoid receptors provided the appropriate tool to isolate an endogenous cannabimimetic eicosanoid, anandamide, from porcine brain. Recent studies indicate that anandamide is a member of a family of fatty acid ethanolamides that may represent a novel class of lipid neurotransmitters. This review discusses recent progress in cannabinoid research with a focus on the receptors for delta9-THC, their coupling to second messenger responses, and the endogenous lipid cannabimimetic, anandamide.

  2. Why do cannabinoid receptors have more than one endogenous ligand?

    PubMed Central

    Di Marzo, Vincenzo; De Petrocellis, Luciano

    2012-01-01

    The endocannabinoid system was revealed following the understanding of the mechanism of action of marijuana's major psychotropic principle, Δ9-tetrahydrocannabinol, and includes two G-protein-coupled receptors (GPCRs; the cannabinoid CB1 and CB2 receptors), their endogenous ligands (the endocannabinoids, the best studied of which are anandamide and 2-arachidonoylglycerol (2-AG)), and the proteins that regulate the levels and activity of these receptors and ligands. However, other minor lipid metabolites different from, but chemically similar to, anandamide and 2-AG have also been suggested to act as endocannabinoids. Thus, unlike most other GPCRs, cannabinoid receptors appear to have more than one endogenous agonist, and it has been often wondered what could be the physiological meaning of this peculiarity. In 1999, it was proposed that anandamide might also activate other targets, and in particular the transient receptor potential of vanilloid type-1 (TRPV1) channels. Over the last decade, this interaction has been shown to occur both in peripheral tissues and brain, during both physiological and pathological conditions. TRPV1 channels can be activated also by another less abundant endocannabinoid, N-arachidonoyldopamine, but not by 2-AG, and have been proposed by some authors to act as ionotropic endocannabinoid receptors. This article will discuss the latest discoveries on this subject, and discuss, among others, how anandamide and 2-AG differential actions at TRPV1 and cannabinoid receptors contribute to making this signalling system a versatile tool available to organisms to fine-tune homeostasis. PMID:23108541

  3. Cannabinoids, cannabinoid receptors and tinnitus.

    PubMed

    Smith, Paul F; Zheng, Yiwen

    2016-02-01

    One hypothesis suggests that tinnitus is a form of sensory epilepsy, arising partly from neuronal hyperactivity in auditory regions of the brain such as the cochlear nucleus and inferior colliculus. Although there is currently no effective drug treatment for tinnitus, anti-epileptic drugs are used in some cases as a potential treatment option. There is increasing evidence to suggest that cannabinoid drugs, i.e. cannabinoid receptor agonists, can also have anti-epileptic effects, at least in some cases and in some parts of the brain. It has been reported that cannabinoid CB1 receptors and the endogenous cannabinoid, 2-arachidonylglycerol (2-AG), are expressed in the cochlear nucleus and that they are involved in the regulation of plasticity. This review explores the question of whether cannabinoid receptor agonists are likely to be pro- or anti-epileptic in the cochlear nucleus and therefore whether cannabinoids and Cannabis itself are likely to make tinnitus better or worse.

  4. Delta9-tetrahydrocannabinol and endogenous cannabinoid anandamide directly potentiate the function of glycine receptors.

    PubMed

    Hejazi, Nadia; Zhou, Chunyi; Oz, Murat; Sun, Hui; Ye, Jiang Hong; Zhang, Li

    2006-03-01

    Anandamide (AEA) and delta9-tetrahydrocannabinol (THC) are endogenous and exogenous ligands, respectively, for cannabinoid receptors. Whereas most of the pharmacological actions of cannabinoids are mediated by CB1 receptors, there is also evidence that these compounds can produce effects that are not mediated by the activation of identified cannabinoid receptors. Here, we report that THC and AEA, in a CB1 receptor-independent manner, cause a significant potentiation of the amplitudes of glycine-activated currents (I(Gly)) in acutely isolated neurons from rat ventral tegmental area (VTA) and in Xenopus laevis oocytes expressing human homomeric (alpha1) and heteromeric (alpha1beta1) subunits of glycine receptors (GlyRs). The potentiation of I(Gly) by THC and AEA is concentration-dependent, with respective EC50 values of 86 +/- 9 and 319 +/- 31 nM for alpha1 homomeric receptors, 73 +/- 8 and 318 +/- 24 nM for alpha1beta1 heteromeric receptors, and 115 +/- 13 and 230 +/- 29 nM for native GlyRs in VTA neurons. The effects of THC and AEA are selective for I(Gly), because GABA-activated current in VTA neurons or in X. laevis oocytes expressing alpha2beta3gamma2 GABA(A) receptor subunits were unaffected by these compounds. The maximal potentiation by THC and AEA was observed at the lowest concentration of glycine; with increasing concentrations of glycine, the potentiation significantly decreased. The site for THC and AEA seems to be distinct from that of the alcohol and volatile anesthetics. The results indicate that THC and AEA, in pharmacologically relevant concentrations, directly potentiate the function of GlyRs through an allosteric mechanism.

  5. The endogenous cannabinoid anandamide inhibits alpha7 nicotinic acetylcholine receptor-mediated responses in Xenopus oocytes.

    PubMed

    Oz, Murat; Ravindran, Arippa; Diaz-Ruiz, Oscar; Zhang, Li; Morales, Marisela

    2003-09-01

    The effect of the endogenous cannabinoid ligand anandamide on the function of the cloned alpha7 subunit of the nicotinic acetylcholine (ACh) receptor expressed in Xenopus oocytes was investigated by using the two-electrode voltage-clamp technique. Anandamide reversibly inhibited nicotine (10 microM) induced-currents in a concentration-dependent manner (10 nM to 30 microM), with an IC50 value of 229.7 +/- 20.4 nM. The effect of anandamide was neither dependent on the membrane potential nor meditated by endogenous Ca2+ dependent Cl- channels since it was unaffected by intracellularly injected BAPTA and perfusion with Ca2+-free bathing solution containing 2 mM Ba2+. Anandamide decreased the maximal nicotine-induced responses without significantly affecting its potency, indicating that it acts as a noncompetitive antagonist on nicotinic acetylcholine (nACh) alpha7 receptors. This effect was not mediated by CB1 or CB2 receptors, as neither the selective CB1 receptor antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboximide hydrochloride (SR 141716A) nor CB2 receptor antagonist N-((1S)-endo-1,3,3-trimethyl-bicyclo-heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR 144528) reduced the inhibition by anandamide. In addition, inhibition of nicotinic responses by anandamide was not sensitive to either pertussis toxin treatment or to the membrane permeable cAMP analog 8-Br-cAMP (0.2 mM). Inhibitors of enzymes involved in anandamide metabolism including phenylmethylsulfonyl fluoride, superoxide dismutase, and indomethacin, or the anandamide transport inhibitor AM404 did not prevent anandamide inhibition of nicotinic responses, suggesting that anandamide itself acted on nicotinic receptors. In conclusion, these results demonstrate that the endogenous cannabinoid anandamide inhibits the function of nACh alpha7 receptors expressed in Xenopus oocytes in a cannabinoid receptor-independent and

  6. The cannabinoid receptors.

    PubMed

    Howlett, Allyn C

    2002-08-01

    Cannabinoid receptors were named because they have affinity for the agonist delta9-tetrahydrocannabinol (delta9-THC), a ligand found in organic extracts from Cannabis sativa. The two types of cannabinoid receptors, CB1 and CB2. are G protein coupled receptors that are coupled through the Gi/o family of proteins to signal transduction mechanisms that include inhibition of adenylyl cyclase, activation of mitogen-activated protein kinase, regulation of calcium and potassium channels (CB1 only), and other signal transduction pathways. A class of the eicosanoid ligands are relevant to lipid-mediated cellular signaling because they serve as endogenous agonists for cannabinoid receptors, and are thus referred to as endocannabinoids. Those compounds identified to date include the eicosanoids arachidonoylethanolamide (anandamide), 2-arachidonoylglycerol and 2-arachidonylglyceryl ether (noladin ether). Several excellent reviews on endocannabinoids and their synthesis, metabolism and function have appeared in recent years. This paper will describe the biological activities, pharmacology, and signal transduction mechanisms for the cannabinoid receptors, with particular emphasis on the responses to the eicosanoid ligands.

  7. Site-specific increases in peripheral cannabinoid receptors and their endogenous ligands in a model of neuropathic pain.

    PubMed

    Mitrirattanakul, Somsak; Ramakul, Navapoln; Guerrero, Andre V; Matsuka, Yoshizo; Ono, Takeshi; Iwase, Hirotate; Mackie, Ken; Faull, Kym F; Spigelman, Igor

    2006-12-15

    Selective activation of the peripheral cannabinoid receptor 1 (CB1R) has been shown to suppress neuropathic pain symptoms in rodents. However, relatively little is known about changes in CB1R and its endogenous ligands during development or maintenance of neuropathic pain. Using immunohistochemistry, Western blot, real-time reverse transcription polymerase chain reaction, as well as liquid chromatography/mass spectrometry, we studied the changes in CB1Rs and endocannabinoids N-arachidonoylethanolamine/anandamide (AEA) and 2-arachidonoylglycerol (2-AG) in rat lumbar (L4 and L5) dorsal root ganglia (DRG) after neuropathic pain induction (L5 spinal nerve ligation: SNL). Immunohistochemistry revealed that in control rats, CB1R is expressed in the majority (76-83%) of nociceptive neurons as indicated by co-labeling with isolectin B4 (IB4) or antibodies recognizing transient receptor potential vanilloid (TRPV1), calcitonin gene related peptide (CGRP), and the NR2C/2D subunits of the N-methyl-D-aspartate receptor. After L5 SNL, CB1R mRNA and protein increases in the ipsilateral uninjured L4 DRG whereas the percentages of CB1R immunoreactive (CB1R-ir) neurons remain unchanged in L4 and L5 DRG. However, for these CB1R-ir neurons, we observe significant increases in percentage of TRPV1-ir cells in ipsilateral L4 DRG, and decreases in percentage of IB4- and CGRP-co-labeled cells in ipsilateral L5 DRG. Levels of both AEA and 2-AG increase significantly only in the ipsilateral L5 DRG. These results are consistent with the preserved analgesic effects of cannabinoids in neuropathic pain and provide a rational framework for the development of peripherally acting endocannabinoid-based therapeutic interventions for neuropathic pain.

  8. Inhibition of leukocyte function and interleukin-2 gene expression by 2-methylarachidonyl-(2'-fluoroethyl)amide, a stable congener of the endogenous cannabinoid receptor ligand anandamide

    SciTech Connect

    Kaplan, Barbara L.F.; Ouyang Yanli; Herring, Amy; Yea, Sung Su; Razdan, Raj; Kaminski, Norbert E. . E-mail: kamins11@msu.edu

    2005-06-01

    Arachidonylethanolamide (anandamide, AEA) has been identified as an endogenous ligand for cannabinoid receptors CB1 and CB2. Characterization of the direct cannabimimetic actions of anandamide has been hampered by its short duration of action and rapid degradation in in vivo and in vitro systems to arachidonic acid, a precursor in the biosynthesis of a broad range of biologically active molecules. In the present studies, we utilized 2-methylarachidonyl-(2'-fluoroethyl)amide (F-Me-AEA), an analog of anandamide resistant to enzymatic degradation, to determine whether F-Me-AEA modulated T cell function similar to that of plant-derived cannabinoids. Indeed, F-Me-AEA at low micromolar concentrations exhibited a marked inhibition of phorbol ester plus calcium ionophore (PMA/Io)-induced IL-2 protein secretion and steady state mRNA expression. Likewise, a modest suppression of the mixed lymphocyte response was observed in the presence of F-Me-AEA indicating an alteration in T cell responsiveness to allogeneic MHC class II antigens. F-Me-AEA was also found to modestly inhibit forskolin-stimulated adenylate cyclase activity in thymocytes and splenocytes, a hallmark of cannabinoid receptor agonists. Further characterization of the influence of F-Me-AEA on the cAMP signaling cascade revealed an inhibition of CREB-1/ATF-1 phosphorylation and subsequently, an inhibition of CRE DNA binding activity. Characterization of nuclear binding proteins further revealed that NF-AT and, to a lesser extent, NF-{kappa}B DNA binding activities were also suppressed. These studies demonstrate that F-Me-AEA modulates T cell function in a similar manner to plant-derived and endogenous cannabinoids and therefore can be utilized as an amidase- and hydrolysis-resistant endogenous cannabinoid.

  9. Control of cannabinoid CB1 receptor function on glutamate axon terminals by endogenous adenosine acting at A1 receptors.

    PubMed

    Hoffman, Alexander F; Laaris, Nora; Kawamura, Masahito; Masino, Susan A; Lupica, Carl R

    2010-01-13

    Marijuana is a widely used drug that impairs memory through interaction between its psychoactive constituent, Delta-9-tetrahydrocannabinol (Delta(9)-THC), and CB(1) receptors (CB1Rs) in the hippocampus. CB1Rs are located on Schaffer collateral (Sc) axon terminals in the hippocampus, where they inhibit glutamate release onto CA1 pyramidal neurons. This action is shared by adenosine A(1) receptors (A1Rs), which are also located on Sc terminals. Furthermore, A1Rs are tonically activated by endogenous adenosine (eADO), leading to suppressed glutamate release under basal conditions. Colocalization of A1Rs and CB1Rs, and their coupling to shared components of signal transduction, suggest that these receptors may interact. We examined the roles of A1Rs and eADO in regulating CB1R inhibition of glutamatergic synaptic transmission in the rodent hippocampus. We found that A1R activation by basal or experimentally increased levels of eADO reduced or eliminated CB1R inhibition of glutamate release, and that blockade of A1Rs with caffeine or other antagonists reversed this effect. The CB1R-A1R interaction was observed with the agonists WIN55,212-2 and Delta(9)-THC and during endocannabinoid-mediated depolarization-induced suppression of excitation. A1R control of CB1Rs was stronger in the C57BL/6J mouse hippocampus, in which eADO levels were higher than in Sprague Dawley rats, and the eADO modulation of CB1R effects was absent in A1R knock-out mice. Since eADO levels and A1R activation are regulated by homeostatic, metabolic, and pathological factors, these data identify a mechanism in which CB1R function can be controlled by the brain adenosine system. Additionally, our data imply that caffeine may potentiate the effects of marijuana on hippocampal function.

  10. The endogenous cannabinoid anandamide inhibits human breast cancer cell proliferation

    PubMed Central

    De Petrocellis, Luciano; Melck, Dominique; Palmisano, Antonella; Bisogno, Tiziana; Laezza, Chiara; Bifulco, Maurizio; Di Marzo, Vincenzo

    1998-01-01

    Anandamide was the first brain metabolite shown to act as a ligand of “central” CB1 cannabinoid receptors. Here we report that the endogenous cannabinoid potently and selectively inhibits the proliferation of human breast cancer cells in vitro. Anandamide dose-dependently inhibited the proliferation of MCF-7 and EFM-19 cells with IC50 values between 0.5 and 1.5 μM and 83–92% maximal inhibition at 5–10 μM. The proliferation of several other nonmammary tumoral cell lines was not affected by 10 μM anandamide. The anti-proliferative effect of anandamide was not due to toxicity or to apoptosis of cells but was accompanied by a reduction of cells in the S phase of the cell cycle. A stable analogue of anandamide (R)-methanandamide, another endogenous cannabinoid, 2-arachidonoylglycerol, and the synthetic cannabinoid HU-210 also inhibited EFM-19 cell proliferation, whereas arachidonic acid was much less effective. These cannabimimetic substances displaced the binding of the selective cannabinoid agonist [3H]CP 55,940 to EFM-19 membranes with an order of potency identical to that observed for the inhibition of EFM-19 cell proliferation. Moreover, anandamide cytostatic effect was inhibited by the selective CB1 receptor antagonist SR 141716A. Cell proliferation was arrested by a prolactin mAb and enhanced by exogenous human prolactin, whose mitogenic action was reverted by very low (0.1–0.5 μM) doses of anandamide. Anandamide suppressed the levels of the long form of the prolactin receptor in both EFM-19 and MCF-7 cells, as well as a typical prolactin-induced response, i.e., the expression of the breast cancer cell susceptibility gene brca1. These data suggest that anandamide blocks human breast cancer cell proliferation through CB1-like receptor-mediated inhibition of endogenous prolactin action at the level of prolactin receptor. PMID:9653194

  11. The Cannabinoid Acids, Analogs and Endogenous Counterparts

    PubMed Central

    Burstein, Sumner H.

    2015-01-01

    The cannabinoid acids are a structurally heterogeneous group of compounds some of which are endogenous molecules and others that are metabolites of phytocannabinoids. The prototypic endogenous substance is N-arachidonoyl glycine (NAgly) that is closely related in structure to the cannabinoid agonist anandamide. The most studied phytocannabinoid is Δ9–THC-11-oic acid, the principal metabolite of Δ9–THC. Both types of acids have in common several biological actions such as low affinity for CB1, anti-inflammatory activity and analgesic properties. This suggests that there may be similarities in their mechanism of action, a point that is discussed in this review. Also presented are reports on analogs of the acids that provide opportunities for the development of novel therapeutic agents, such as ajulemic acid. PMID:24731541

  12. Epileptiform activity in the CA1 region of the hippocampus becomes refractory to attenuation by cannabinoids in part because of endogenous γ-aminobutyric acid type B receptor activity.

    PubMed

    Messer, Ricka D; Levine, Eric S

    2012-07-01

    The anticonvulsant properties of marijuana have been known for centuries. The recently characterized endogenous cannabinoid system thus represents a promising target for novel anticonvulsant agents; however, administration of exogenous cannabinoids has shown mixed results in both human epilepsy and animal models. The ability of cannabinoids to attenuate release of both excitatory and inhibitory neurotransmitters may explain the variable effects of cannabinoids in different models of epilepsy, but this has not been well explored. Using acute mouse brain slices, we monitored field potentials in the CA1 region of the hippocampus to characterize systematically the effects of the cannabinoid agonist WIN55212-2 (WIN) on evoked basal and epileptiform activity. WIN, acting presynaptically, significantly reduced the amplitude and slope of basal field excitatory postsynaptic potentials as well as stimulus-evoked epileptiform responses induced by omission of magnesium from the extracellular solution. In contrast, the combination of omission of magnesium plus elevation of potassium induced an epileptiform response that was refractory to attenuation by WIN. The effect of WIN in this model was partially restored by blocking γ-aminobutyric acid type B (GABA(B) ), but not GABA(A) , receptors. Subtle differences in models of epileptiform activity can profoundly alter the efficacy of cannabinoids. Endogenous GABA(B) receptor activation played a role in the decreased cannabinoid sensitivity observed for epileptiform activity induced by omission of magnesium plus elevation of potassium. These results suggest that interplay between presynaptic G protein-coupled receptors with overlapping downstream targets may underlie the variable efficacy of cannabinoids in different models of epilepsy.

  13. Immunoactive effects of cannabinoids: considerations for the therapeutic use of cannabinoid receptor agonists and antagonists.

    PubMed

    Greineisen, William E; Turner, Helen

    2010-05-01

    The active constituents of Cannabis sativa have been used for centuries as recreational drugs and medicinal agents. Today, marijuana is the most prevalent drug of abuse in the United States and, conversely, therapeutic use of marijuana constituents are gaining mainstream clinical and political acceptance. Given the documented contributions of endocannabinoid signaling to a range of physiological systems, including cognitive function, and the control of eating behaviors, it is unsurprising that cannabinoid receptor agonists and antagonists are showing significant clinical potential. In addition to the neuroactive effects of cannabinoids, an emerging body of data suggests that both endogenous and exogenous cannabinoids are potently immunoactive. The central premise of this review article is that the immunological effects of cannabinoids should be considered in the context of each prescribing decision. We present evidence that the immunological effects of cannabinoid receptor agonists and antagonists are highly relevant to the spectrum of disorders for which cannabinoid therapeutics are currently offered.

  14. Synthetic and endogenous cannabinoids protect retinal neurons from AMPA excitotoxicity in vivo, via activation of CB1 receptors: Involvement of PI3K/Akt and MEK/ERK signaling pathways.

    PubMed

    Kokona, Despina; Thermos, Kyriaki

    2015-07-01

    Cannabinoids have been suggested to protect retinal ganglion cells in different models of toxicity, but their effects on other retinal neurons are poorly known. We investigated the neuroprotective actions of the endocannabinoid N-arachidonoyl ethanolamine (Anandamide/AEA) and the synthetic cannabinoids R1-Methanandamide (MethAEA) and HU-210, in an in vivo retinal model of AMPA excitotoxicity, and the mechanisms involved in the neuroprotection. Sprague-Dawley rats were intravitreally injected with PBS or AMPA in the absence or presence of the cannabinoid agonists. Brain nitric oxide synthase (bNOS) and choline acetyltransferase (ChAT) immunoreactivity (IR), as well as TUNEL staining, assessed the AMPA-induced retinal amacrine cell loss and the dose-dependent neuroprotection afforded by cannabinoids. The CB1 receptor selective antagonist AM251 and the PI3K/Akt inhibitor wortmannin reversed the cannabinoid-induced neuroprotection, suggesting the involvement of CB1 receptors and the PI3K/Akt pathway in cannabinoids' actions. Experiments with the CB2 agonist JWH015 and [(3)H]CP55940 radioligand binding suggested that the CB2 receptor is not involved in the neuroprotection. AEA and HU-210 induced phosphorylation of Akt but only AEA induced phosphorylation of ERK1/2 kinases, as revealed by western blot analysis. To investigate the role of caspase-3 in the AMPA-induced cell death, the caspase-3 inhibitor Z-DEVD-FMK was co-injected with AMPA. Z-DEVD-FMK had no effect on AMPA excitotoxicity. Moreover, no difference was observed in the phosphorylation of SAPK/JNK kinases between PBS- and AMPA-treated retinas. These results suggest that endogenous and synthetic cannabinoids protect retinal amacrine neurons from AMPA excitotoxicity in vivo via a mechanism involving the CB1 receptors, and the PI3K/Akt and/or MEK/ERK1/2 signaling pathways.

  15. Cellular approaches to the interaction between cannabinoid receptor ligands and nicotinic acetylcholine receptors.

    PubMed

    Oz, Murat; Al Kury, Lina; Keun-Hang, Susan Yang; Mahgoub, Mohamed; Galadari, Sehamuddin

    2014-05-15

    Cannabinoids are among the earliest known drugs to humanity. Cannabis plant contains various phytochemicals that bind to cannabinoid receptors. In addition, synthetic and endogenously produced cannabinoids (endocannabinoids) constitute other classes of cannabinoid receptor ligands. Although many pharmacological effects of these cannabinoids are mediated by the activation of cannabinoid receptors, recent studies indicate that cannabinoids also modulate the functions of various integral membrane proteins including ion channels, receptors, neurotransmitter transporters, and enzymes by mechanism(s) not involving the activation of known cannabinoid receptors. Currently, the mechanisms of these effects were not fully understood. However, it is likely that direct actions of cannabinoids are closely linked to their lipophilic structures. This report will focus on the actions of cannabinoids on nicotinic acetylcholine receptors and will examine the results of recent studies in this field. In addition some mechanistic approaches will be provided. The results discussed in this review indicate that, besides cannabinoid receptors, further molecular targets for cannabinoids exist and that these targets may represent important novel sites to alter neuronal excitability.

  16. Cannabinoid and cannabinoid-like receptors in microglia, astrocytes and astrocytomas

    PubMed Central

    Stella, Nephi

    2010-01-01

    CB1 and CB2 receptors are activated by a plethora of cannabinoid compounds, be they endogenously-produced, plant-derived or synthetic. These receptors are expressed by microglia, astrocytes and astrocytomas, and their activation regulates these cells’ differentiation, functions and viability. Recent studies show that glial cells also express cannabinoid-like receptors, and that their activation regulates different cell functions, but also control cell viability. This review summarizes this evidence, and discusses how selective compounds targeting cannabinoid-like receptors constitute promising therapeutics to manage neuroinflammation and eradicate malignant astrocytomas. Importantly, the selective targeting of cannabinoid-like receptors should provide therapeutic relieve without inducing the typical psychotropic effects and possible addictive properties associated with the use of Δ9-tetrahydrocannabinol, the main psychotropic ingredient produced by the plant Cannabis sativa. PMID:20468046

  17. Cannabinoid receptor type-1: breaking the dogmas

    PubMed Central

    Busquets Garcia, Arnau; Soria-Gomez, Edgar; Bellocchio, Luigi; Marsicano, Giovanni

    2016-01-01

    The endocannabinoid system (ECS) is abundantly expressed in the brain. This system regulates a plethora of physiological functions and is composed of cannabinoid receptors, their endogenous ligands (endocannabinoids), and the enzymes involved in the metabolism of endocannabinoids. In this review, we highlight the new advances in cannabinoid signaling, focusing on a key component of the ECS, the type-1 cannabinoid receptor (CB 1). In recent years, the development of new imaging and molecular tools has demonstrated that this receptor can be distributed in many cell types (e.g., neuronal or glial cells) and intracellular compartments (e.g., mitochondria). Interestingly, cellular and molecular effects are differentially mediated by CB 1 receptors according to their specific localization (e.g., glutamatergic or GABAergic neurons). Moreover, this receptor is expressed in the periphery, where it can modulate periphery-brain connections. Finally, the better understanding of the CB 1 receptor structure led researchers to propose interesting and new allosteric modulators. Thus, the advances and the new directions of the CB 1 receptor field will provide new insights and better approaches to profit from its interesting therapeutic profile. PMID:27239293

  18. Exogenous delta⁹-tetrahydrocannabinol influences circulating endogenous cannabinoids in humans.

    PubMed

    Walter, Carmen; Ferreirós, Nerea; Bishay, Philipp; Geisslinger, Gerd; Tegeder, Irmgard; Lötsch, Jörn

    2013-10-01

    Delta⁹-tetrahydrocannabinol (THC) competes with the endogenous cannabinoids arachidonoyl ethanolamide (anandamide) and 2-arachidonoyl glycerol (2-AG) at cannabinoid receptors. This may cause adaptive changes in the endocannabinoid signaling cascade with possible consequences for the biological functions of the endocannabinoid system. We show that administration of a single oral dose of 20 mg THC to 30 healthy volunteers resulted in higher circulating concentrations of anandamide, 2-AG, palmitoyl ethanolamide, and oleoylethanolamide at 2 and 3 hours after administration as compared with placebo. At 2 hours after THC administration, changes in oleoylethanolamide plasma concentrations from baseline were linearly related to the THC plasma concentrations. In rats, treatment with the CB₁/CB₂ agonist WIN 55,212 also increased plasma endocannabinoid concentrations. However, this was associated with a decrease of ethanolamide endocannabinoids in specific brain regions including spinal cord, cortex, and hypothalamus; whereas 2-arachidonoyl glycerol increased in the cortex. Thus, administration of THC to human volunteers influenced the concentrations of circulating endocannabinoids, which was mimicked by WIN-55,212 in rats, suggesting that exogenous cannabinoids may lead to changes in the endocannabinoid system that can be detected in plasma.

  19. Functional role of cannabinoid receptors in urinary bladder

    PubMed Central

    Tyagi, Pradeep; Tyagi, Vikas; Yoshimura, Naoki; Chancellor, Michael

    2010-01-01

    Cannabinoids, the active components of Cannabis sativa (maijuana), and their derivatives produce a wide spectrum of central and peripheral effects, some of which may have clinical applications. The discovery of specific cannabinoid receptors and a family of endogenous ligands of those receptors has attracted much attention to the general cannabinoid pharmacology. In recent years, studies on the functional role of cannabinoid receptors in bladder have been motivated by the therapeutic effects of cannabinoids on voiding dysfunction in multiple sclerosis patients. In this review, we shall summarize the literature on the expression of cannabinoid receptors in urinary bladder and the peripheral influence of locally and systemically administered cannabinoids in the bladder. The ongoing search for cannabinoid-based therapeutic strategies devoid of psychotropic effects can be complemented with local delivery into bladder by the intravesical route. A greater understanding of the role of the peripheral CB1 and CB2 receptor system in lower urinary tract is necessary to allow the development of new treatment for pelvic disorders. PMID:20535281

  20. Oxaza adamantyl cannabinoids. A new class of cannabinoid receptor probes.

    PubMed

    Le Goanvic, David; Tius, Marcus A

    2006-09-29

    The preparation of C3 oxaza adamantyl cannabinoids has been described starting from phloroglucinol. Straightforward manipulations of the aromatic ring lead to a bromononaflate that is a benzyne precursor and that serves as a common intermediate for the synthesis of diverse C3-substituted tricyclic cannabinoids. Generation of the benzyne in the presence of an oxaza adamantyl amide anion results in efficient and regiospecific addition to C3 of the aromatic ring. This represents an attractive strategy for the synthesis of classical tricyclic cannabinoids that bear a modified aromatic appendage. The oxaza adamantyl cannabinoids that have been prepared represent a new class of ligands for the CB1 and CB2 receptors.

  1. TRP channel cannabinoid receptors in skin sensation, homeostasis, and inflammation.

    PubMed

    Caterina, Michael J

    2014-11-19

    In the skin, cannabinoid lipids, whether of endogenous or exogenous origin, are capable of regulating numerous sensory, homeostatic, and inflammatory events. Although many of these effects are mediated by metabotropic cannabinoid receptors, a growing body of evidence has revealed that multiple members of the transient receptor potential (TRP) ion channel family can act as "ionotropic cannabinoid receptors". Furthermore, many of these same TRP channels are intimately involved in cutaneous processes that include the initiation of pain, temperature, and itch perception, the maintenance of epidermal homeostasis, the regulation of hair follicles and sebaceous glands, and the modulation of dermatitis. Ionotropic cannabinoid receptors therefore represent potentially attractive targets for the therapeutic use of cannabinoids to treat sensory and dermatological diseases. Furthermore, the interactions between neurons and other cell types that are mediated by cutaneous ionotropic cannabinoid receptors are likely to be recapitulated during physiological and pathophysiological processes in the central nervous system and elsewhere, making the skin an ideal setting in which to dissect general complexities of cannabinoid signaling.

  2. TRP Channel Cannabinoid Receptors in Skin Sensation, Homeostasis, and Inflammation

    PubMed Central

    2015-01-01

    In the skin, cannabinoid lipids, whether of endogenous or exogenous origin, are capable of regulating numerous sensory, homeostatic, and inflammatory events. Although many of these effects are mediated by metabotropic cannabinoid receptors, a growing body of evidence has revealed that multiple members of the transient receptor potential (TRP) ion channel family can act as “ionotropic cannabinoid receptors”. Furthermore, many of these same TRP channels are intimately involved in cutaneous processes that include the initiation of pain, temperature, and itch perception, the maintenance of epidermal homeostasis, the regulation of hair follicles and sebaceous glands, and the modulation of dermatitis. Ionotropic cannabinoid receptors therefore represent potentially attractive targets for the therapeutic use of cannabinoids to treat sensory and dermatological diseases. Furthermore, the interactions between neurons and other cell types that are mediated by cutaneous ionotropic cannabinoid receptors are likely to be recapitulated during physiological and pathophysiological processes in the central nervous system and elsewhere, making the skin an ideal setting in which to dissect general complexities of cannabinoid signaling. PMID:24915599

  3. Cannabinoid Receptors: Nomenclature and Pharmacological Principles

    PubMed Central

    Console-Bram, Linda; Marcu, Jahan; Abood, Mary E.

    2012-01-01

    The CB1 and CB2 cannabinoid receptors are members of the G protein-coupled receptor (GPCR) family that are pharmacologically well defined. However, the discovery of additional sites of action for endocannabinoids as well as synthetic cannabinoid compounds suggests the existence of additional cannabinoid receptors. Here we review this evidence, as well as the current nomenclature for classifying a target as a cannabinoid receptor. Basic pharmacological definitions, principles and experimental conditions are discussed in order to place in context the mechanisms underlying cannabinoid receptor activation. Constitutive (agonist-independent) activity is observed with the overexpression of many GPCRs, including cannabinoid receptors. Allosteric modulators can alter the pharmacological responses of cannabinoid receptors. The complex molecular architecture of each of the cannabinoid receptors allows for a single receptor to recognize multiple classes of compounds and produce an array of distinct downstream effects. Natural polymorphisms and alternative splice variants may also contribute to their pharmacological diversity. As our knowledge of the distinct differences grows, we may be able to target select receptor conformations and their corresponding pharmacological responses. Importantly, the basic biology of the endocannabinoid system will continue to be revealed by ongoing investigations. PMID:22421596

  4. Role of the Endogenous Cannabinoid System in Nicotine Addiction: Novel Insights

    PubMed Central

    Gamaleddin, Islam Hany; Trigo, Jose M.; Gueye, Aliou B.; Zvonok, Alexander; Makriyannis, Alexandros; Goldberg, Steven R.; Le Foll, Bernard

    2015-01-01

    Several lines of evidence have shown that the endogenous cannabinoids are implicated in several neuropsychiatric diseases. Notably, preclinical and human clinical studies have shown a pivotal role of the cannabinoid system in nicotine addiction. The CB1 receptor inverse agonist/antagonist rimonabant (also known as SR141716) was effective to decrease nicotine-taking and nicotine-seeking in rodents, as well as the elevation of dopamine induced by nicotine in brain reward area. Rimonabant has been shown to improve the ability of smokers to quit smoking in randomized clinical trials. However, rimonabant was removed from the market due to increased risk of psychiatric side-effects observed in humans. Recently, other components of the endogenous cannabinoid system have been explored. Here, we present the recent advances on the understanding of the role of the different components of the cannabinoid system on nicotine’s effects. Those recent findings suggest possible alternative ways of modulating the cannabinoid system that could have implication for nicotine dependence treatment. PMID:25859226

  5. Peripheral metabolic effects of endocannabinoids and cannabinoid receptor blockade.

    PubMed

    Engeli, Stefan

    2008-01-01

    The endocannabinoid system consists of endogenous arachidonic acid derivates that activate cannabinoid receptors. The two most prominent endocannabinoids are anandamide and 2-arachidonoyl glycerol. In obesity, increased concentrations of circulating and tissue endocannabinoid levels have been described, suggesting increased activity of the endocannabinoid system. Increased availability of endocannabinoids in obesity may over-stimulate cannabinoid receptors. Blockade of cannabinoid type 1 (CB1) receptors was the only successful clinical development of an anti-obesity drug during the last decade. Whereas blockade of CB1 receptors acutely reduces food intake, the long-term effects on metabolic regulation are more likely mediated by peripheral actions in liver, skeletal muscle, adipose tissue, and the pancreas. Lipogenic effects of CB1 receptor signalling in liver and adipose tissue may contribute to regional adipose tissue expansion and insulin resistance in the fatty liver. The association of circulating 2-arachidonoyl glycerol levels with decreased insulin sensitivity strongly suggests further exploration of the role of endocannabinoid signalling for insulin sensitivity in skeletal muscle, liver, and adipose tissue. A few studies have suggested a specific role for the regulation of adiponectin secretion from adipocytes by endocannabinoids, but that has to be confirmed by more experiments. Also, the potential role of CB1 receptor blockade for the stimulation of energy expenditure needs to be studied in the future. Despite the current discussion of safety issues of cannabinoid receptor blockade, these findings open a new and exciting perspective on endocannabinoids as regulators of body weight and metabolism.

  6. Reducing cannabinoid abuse and preventing relapse by enhancing endogenous brain levels of kynurenic acid

    PubMed Central

    Justinova, Zuzana; Mascia, Paola; Wu, Hui-Qiu; Secci, Maria E.; Redhi, Godfrey H.; Panlilio, Leigh V.; Scherma, Maria; Barnes, Chanel; Parashos, Alexandra; Zara, Tamara; Fratta, Walter; Solinas, Marcello; Pistis, Marco; Bergman, Jack; Kangas, Brian D.; Ferré, Sergi; Tanda, Gianluigi; Schwarcz, Robert; Goldberg, Steven R.

    2013-01-01

    In the reward circuitry of the brain, alpha-7-nicotinic acetylcholine receptors (α7nAChRs) modulate effects of delta-9-tetrahydrocannabinol (THC), marijuana’s main psychoactive ingredient. Kynurenic acid (KYNA) is an endogenous negative allosteric modulator of α7nAChRs. Here we report that the kynurenine 3-monooxygenase (KMO) inhibitor Ro 61-8048 increases brain KYNA levels and attenuates cannabinoid-induced increases in extracellular dopamine in reward-related brain areas. In the self-administration model of drug abuse, Ro 61-8048 reduced the rewarding effects of THC and the synthetic cannabinoid WIN 55,212-2 in squirrel monkeys and rats, respectively, and it also prevented relapse to drug-seeking induced by re-exposure to cannabinoids or cannabinoid-associated cues. The effects of enhancing endogenous KYNA levels with Ro 61-8048 were prevented by positive allosteric modulators of α7nAChRs. Despite a clear need, there are currently no medications approved for treatment of marijuana dependence. Modulation of KYNA provides a novel pharmacological strategy for achieving abstinence from marijuana and preventing relapse. PMID:24121737

  7. Reducing cannabinoid abuse and preventing relapse by enhancing endogenous brain levels of kynurenic acid.

    PubMed

    Justinova, Zuzana; Mascia, Paola; Wu, Hui-Qiu; Secci, Maria E; Redhi, Godfrey H; Panlilio, Leigh V; Scherma, Maria; Barnes, Chanel; Parashos, Alexandra; Zara, Tamara; Fratta, Walter; Solinas, Marcello; Pistis, Marco; Bergman, Jack; Kangas, Brian D; Ferré, Sergi; Tanda, Gianluigi; Schwarcz, Robert; Goldberg, Steven R

    2013-11-01

    In the reward circuitry of the brain, α-7-nicotinic acetylcholine receptors (α7nAChRs) modulate effects of Δ(9)-tetrahydrocannabinol (THC), marijuana's main psychoactive ingredient. Kynurenic acid (KYNA) is an endogenous negative allosteric modulator of α7nAChRs. Here we report that the kynurenine 3-monooxygenase (KMO) inhibitor Ro 61-8048 increases brain KYNA levels and attenuates cannabinoid-induced increases in extracellular dopamine in reward-related brain areas. In the self-administration model of drug abuse, Ro 61-8048 reduced the rewarding effects of THC and the synthetic cannabinoid WIN 55,212-2 in squirrel monkeys and rats, respectively, and it also prevented relapse to drug-seeking induced by reexposure to cannabinoids or cannabinoid-associated cues. The effects of enhancing endogenous KYNA levels with Ro 61-8048 were prevented by positive allosteric modulators of α7nAChRs. Despite a clear need, there are no medications approved for treatment of marijuana dependence. Modulation of KYNA offers a pharmacological strategy for achieving abstinence from marijuana and preventing relapse.

  8. Anandamide, an endogenous cannabinoid, inhibits Shaker-related voltage-gated K+ channels.

    PubMed

    Poling, J S; Rogawski, M A; Salem, N; Vicini, S

    1996-01-01

    Anandamide has been identified in porcine brain as an endogenous cannabinoid receptor ligand and is believed to be a counterpart to the psychoactive component of marijuana, delta 9-tetrahydrocannabinol (delta 9-THC). Here we report that anandamide directly inhibits (IC50, 2.7 muM) Shaker-related Kv1.2 K+ channels that are found ubiquitously in the mammalian brain. Delta 9-THC also inhibited Kv1.2 channels with comparable potency (IC50, 2.4 muM), as did several N-acyl-ethanolamides with cannabinoid receptor binding activity. Potassium current inhibition occurred through a pertussis toxin-insensitive mechanism and was not prevented by the cannabinoid receptor antagonist SR141716A. Utilizing excised patches of Kv1.2 channel-rich membrane as a rapid and sensitive bioassay, we found that phospholipase D stimulated the release of an endogenous anandamide-like K+ channel blocker from rat brain slices. Structure-activity studies were consistent with the possibility that the released blocker was either anandamide or another N-acyl-ethanolamide.

  9. CB1 cannabinoid receptor-mediated neurite remodeling in mouse neuroblastoma N1E-115 cells.

    PubMed

    Zhou, D; Song, Z H

    2001-08-15

    The morphological remodeling of neuronal cells influences neurogenesis and brain functions. We hypothesize that psychoactive and neurotoxic effects of cannabinoids may be mediated, at least in part, by their morphoregulatory activities. In the present study, mouse neuroblastoma N1E-115 cells were used as an in vitro model to investigate cannabinoid-induced neurite remodeling effects and to identify the involvement of cannabinoid receptors in this neurite remodeling process. Using reverse transcription-polymerase chain reaction and immunofluorescence microscopy, the endogenously expressed CB1, but not CB2, cannabinoid receptors were detected in morphologically differentiated N1E-115 cells. Activation of these natively expressed CB1 cannabinoid receptors by cannabinoid agonist HU-210 led to a concentration-dependent inhibition of adenylate cyclase activity. Importantly, HU-210 treatment induced neurite retraction in a concentration-dependent manner. Pretreatment of N1E-115 cells with a CB1 antisense oligodeoxynucleotide (ODN) suppressed HU-210-induced inhibition of forskolin-stimulated cAMP accumulation, indicating that the knocking down of functional CB1 cannabinoid receptor expression was achieved. Antisense ODN pretreatment also abolished HU-210-induced neurite retraction, demonstrating the involvement of CB1 cannabinoid receptors in mediating the neurite remodeling effects of HU-210. In addition, reversing HU-210-induced intracellular cAMP declination by 8-Br-cAMP partially prevented HU-210-induced neurite retraction, indicating the involvement of cAMP-dependent signaling pathways in mediating the neurite remodeling function of CB1 cannabinoid receptors in N1E-115 cells. These data demonstrate that neurite remodeling is a newly discovered function of CB1 cannabinoid receptors. This morphoregulatory function of CB1 cannabinoid receptors might be a new mechanism that mediates the psychoactive and neurotoxic effects of cannabinoids in developing and adult brain.

  10. Exogenous and endogenous cannabinoids control synaptic transmission in mice nucleus accumbens.

    PubMed

    Robbe, David; Alonso, Gerard; Manzoni, Oliver J

    2003-11-01

    Addictive drugs are thought to alter normal brain function and cause the remodeling of synaptic functions in areas important to memory and reward. Excitatory transmission to the nucleus accumbens (NAc) is involved in the actions of most drugs of abuse, including cannabis. We have explored the functions of the endocannabinoid system at the prefrontal cortex-NAc synapses. Immunocytochemistry showed cannabinoid receptor (CB1) expression on axonal terminals making contacts with NAc neurons. In NAc slices, synthetic cannabinoids inhibit spontaneous and evoked glutamate-mediated transmission through presynaptic activation of presynaptic K+ channels and GABA-mediated transmission most likely via a direct presynaptic action on the vesicular release machinery. How does synaptic activity lead to the production of endogenous cannabinoids (eCBs) in the NAc? More generally, do eCBs participate in long-term synaptic plasticity in the brain? We found that tetanic stimulation (mimicking naturally occurring frequencies) of prelimbic glutamatergic afferents induced a presynaptic LTD dependent on eCB and CB1 receptors (eCB-LTD). Induction of eCB-LTD required postsynaptic activation of mGlu5 receptors and a rise in postsynaptic Ca2+ from ryanodine-sensitive intracellular Ca2+ stores. This retrograde signaling cascade involved postsynaptic eCB release and activation of presynaptic CB1 receptors. In the NAc, eCB-LTD might be part of a negative feedback loop, reducing glutamatergic synaptic strength during sustained cortical activity. The fact that this new form of LTD was occluded by an exogenous cannabinoid suggested that cannabis derivatives, such as marijuana, may alter normal eCB-mediated synaptic plasticity. These data suggest a major role of the eCB system in long-term synaptic plasticity and give insights into how cannabis derivatives, such as marijuana, alter normal eCB functions in the brain reward system.

  11. Interaction between Cannabinoid System and Toll-Like Receptors Controls Inflammation

    PubMed Central

    2016-01-01

    Since the discovery of the endocannabinoid system consisting of cannabinoid receptors, endogenous ligands, and biosynthetic and metabolizing enzymes, interest has been renewed in investigating the promise of cannabinoids as therapeutic agents. Abundant evidence indicates that cannabinoids modulate immune responses. An inflammatory response is triggered when innate immune cells receive a danger signal provided by pathogen- or damage-associated molecular patterns engaging pattern-recognition receptors. Toll-like receptor family members are prominent pattern-recognition receptors expressed on innate immune cells. Cannabinoids suppress Toll-like receptor-mediated inflammatory responses. However, the relationship between the endocannabinoid system and innate immune system may not be one-sided. Innate immune cells express cannabinoid receptors and produce endogenous cannabinoids. Hence, innate immune cells may play a role in regulating endocannabinoid homeostasis, and, in turn, the endocannabinoid system modulates local inflammatory responses. Studies designed to probe the interaction between the innate immune system and the endocannabinoid system may identify new potential molecular targets in developing therapeutic strategies for chronic inflammatory diseases. This review discusses the endocannabinoid system and Toll-like receptor family and evaluates the interaction between them. PMID:27597805

  12. Ligands for cannabinoid receptors, promising anticancer agents.

    PubMed

    Nikan, Marjan; Nabavi, Seyed Mohammad; Manayi, Azadeh

    2016-02-01

    Cannabinoid compounds are unique to cannabis and provide some interesting biological properties. These compounds along with endocannabinoids, a group of neuromodulator compounds in the body especially in brain, express their effects by activation of G-protein-coupled cannabinoid receptors, CB1 and CB2. There are several physiological properties attributed to the endocannabinoids including pain relief, enhancement of appetite, blood pressure lowering during shock, embryonic development, and blocking of working memory. On the other hand, activation of endocannabinoid system may be suppresses evolution and progression of several types of cancer. According to the results of recent studies, CB receptors are over-expressed in cancer cell lines and application of multiple cannabinoid or cannabis-derived compounds reduce tumor size through decrease of cell proliferation or induction of cell cycle arrest and apoptosis along with desirable effect on decrease of tumor-evoked pain. Therefore, modulation of endocannabinoid system by inhibition of fatty acid amide hydrolase (FAAH), the enzyme, which metabolized endocannabinoids, or application of multiple cannabinoid or cannabis-derived compounds, may be appropriate for the treatment of several cancer subtypes. This review focuses on how cannabinoid affect different types of cancers.

  13. Targeting the endocannabinoid system with cannabinoid receptor agonists: pharmacological strategies and therapeutic possibilities.

    PubMed

    Pertwee, Roger G

    2012-12-05

    Human tissues express cannabinoid CB(1) and CB(2) receptors that can be activated by endogenously released 'endocannabinoids' or exogenously administered compounds in a manner that reduces the symptoms or opposes the underlying causes of several disorders in need of effective therapy. Three medicines that activate cannabinoid CB(1)/CB(2) receptors are now in the clinic: Cesamet (nabilone), Marinol (dronabinol; Δ(9)-tetrahydrocannabinol (Δ(9)-THC)) and Sativex (Δ(9)-THC with cannabidiol). These can be prescribed for the amelioration of chemotherapy-induced nausea and vomiting (Cesamet and Marinol), stimulation of appetite (Marinol) and symptomatic relief of cancer pain and/or management of neuropathic pain and spasticity in adults with multiple sclerosis (Sativex). This review mentions several possible additional therapeutic targets for cannabinoid receptor agonists. These include other kinds of pain, epilepsy, anxiety, depression, Parkinson's and Huntington's diseases, amyotrophic lateral sclerosis, stroke, cancer, drug dependence, glaucoma, autoimmune uveitis, osteoporosis, sepsis, and hepatic, renal, intestinal and cardiovascular disorders. It also describes potential strategies for improving the efficacy and/or benefit-to-risk ratio of these agonists in the clinic. These are strategies that involve (i) targeting cannabinoid receptors located outside the blood-brain barrier, (ii) targeting cannabinoid receptors expressed by a particular tissue, (iii) targeting upregulated cannabinoid receptors, (iv) selectively targeting cannabinoid CB(2) receptors, and/or (v) adjunctive 'multi-targeting'.

  14. Targeting the endocannabinoid system with cannabinoid receptor agonists: pharmacological strategies and therapeutic possibilities

    PubMed Central

    Pertwee, Roger G.

    2012-01-01

    Human tissues express cannabinoid CB1 and CB2 receptors that can be activated by endogenously released ‘endocannabinoids’ or exogenously administered compounds in a manner that reduces the symptoms or opposes the underlying causes of several disorders in need of effective therapy. Three medicines that activate cannabinoid CB1/CB2 receptors are now in the clinic: Cesamet (nabilone), Marinol (dronabinol; Δ9-tetrahydrocannabinol (Δ9-THC)) and Sativex (Δ9-THC with cannabidiol). These can be prescribed for the amelioration of chemotherapy-induced nausea and vomiting (Cesamet and Marinol), stimulation of appetite (Marinol) and symptomatic relief of cancer pain and/or management of neuropathic pain and spasticity in adults with multiple sclerosis (Sativex). This review mentions several possible additional therapeutic targets for cannabinoid receptor agonists. These include other kinds of pain, epilepsy, anxiety, depression, Parkinson's and Huntington's diseases, amyotrophic lateral sclerosis, stroke, cancer, drug dependence, glaucoma, autoimmune uveitis, osteoporosis, sepsis, and hepatic, renal, intestinal and cardiovascular disorders. It also describes potential strategies for improving the efficacy and/or benefit-to-risk ratio of these agonists in the clinic. These are strategies that involve (i) targeting cannabinoid receptors located outside the blood-brain barrier, (ii) targeting cannabinoid receptors expressed by a particular tissue, (iii) targeting upregulated cannabinoid receptors, (iv) selectively targeting cannabinoid CB2 receptors, and/or (v) adjunctive ‘multi-targeting’. PMID:23108552

  15. Functional CB2 type cannabinoid receptors at CNS synapses.

    PubMed

    Morgan, Nicola H; Stanford, Ian M; Woodhall, Gavin L

    2009-09-01

    To date, it has been thought that cannabinoid receptors in CNS are primarily of the CB1R subtype, with CB2R expressed only in glia and peripheral tissues. However, evidence for the expression of CB2 type cannabinoid receptors at neuronal sites in the CNS is building through anatomical localization of receptors and mRNA in neurons and behavioural studies of central effects of CB2R agonists. In the medial entorhinal area of the rat, we found that blockade of CB1R did not occlude suppression of GABAergic inhibition by the non-specific endogenous cannabinoid 2-AG, suggesting that CB1R could not account fully for the effects of 2-AG. Suppression could be mimicked using the CB2R agonist JWH-133 and reversed by the CB2R inverse agonist AM-630, indicating the presence of functional CB2R. When we reversed the order of drug application AM-630 blocked the effects of the CB2R agonist JWH-133, but not the CB1R inverse agonist LY320135. JTE-907, a CB2R inverse agonist structurally unrelated to AM-630 elicited increased GABAergic neurotransmission at picomolar concentrations. Analysis of mIPSCs revealed that CB2R effects were restricted to action potential dependent, but not action potential independent GABA release. These data provide pharmacological evidence for functional CB2R at CNS synapses.

  16. Rimonabant, a selective cannabinoid1 receptor antagonist, protects against light-induced retinal degeneration in vitro and in vivo.

    PubMed

    Imamura, Tomoyo; Tsuruma, Kazuhiro; Inoue, Yuki; Otsuka, Tomohiro; Ohno, Yuta; Ogami, Shiho; Yamane, Shinsaku; Shimazawa, Masamitsu; Hara, Hideaki

    2017-03-16

    The endocannabinoid system is involved in some neurodegenerative diseases such as Alzheimer's disease. An endogenous constellation of proteins related to cannabinoid1 receptor signaling, including free fatty acids, diacylglycerol lipase, and N-acylethanolamine-hydrolyzing acid amidase, are localized in the murine retina. Moreover, the expression levels of endogenous agonists of cannabinoid receptors are changed in the vitreous fluid. However, the role of the endocannabinoid system in the retina, particularly in the light-induced photoreceptor degeneration, remains unknown. Therefore, we investigated involvement of the cannabinoid1 receptor in light-induced retinal degeneration using in vitro and in vivo models. To evaluate the effect of cannabinoid1 receptors in light irradiation-induced cell death, the mouse retinal cone-cell line (661W) was treated with a cannabinoid1 receptor antagonist, rimonabant. Time-dependent changes of expression and localization of retinal cannabinoid1 receptors were measured using Western blot and immunostaining. Retinal damage was induced in mice by exposure to light, followed by intravitreal injection of rimonabant. Electroretinograms and histologic analyses were performed. Rimonabant suppressed light-induced photoreceptor cell death. Cannabinoid1 receptor expression was upregulated by light exposure. Treatment with rimonabant improved both a- and b-wave amplitudes and the thickness of the outer nuclear layer. These results suggest that the cannabinoid1 receptor is involved in light-induced retinal degeneration and it may represent a therapeutic target in the light-induced photoreceptor degeneration related diseases.

  17. Functional CB1 cannabinoid receptors in human vascular endothelial cells.

    PubMed Central

    Liu, J; Gao, B; Mirshahi, F; Sanyal, A J; Khanolkar, A D; Makriyannis, A; Kunos, G

    2000-01-01

    Cannabinoid CB1 receptor mRNA was detected using reverse transcription-polymerase chain reaction (RT-PCR) in endothelial cells from human aorta and hepatic artery and in the ECV304 cell line derived from human umbilical vein endothelial cells. CB1 receptor-binding sites were detected by the high-affinity antagonist radioligand [(125)I]AM-251. In ECV304 cells, both the highly potent synthetic cannabinoid agonist HU-210 and the endogenous ligand anandamide induce activation of mitogen-activated protein (MAP) kinase, and the effect of HU-210 was completely blocked, whereas the effect of anandamide was partially inhibited by SR141716A, a selective CB1 receptor antagonist. Transfection of ECV304 cells with CB1 receptor antisense, but not sense, oligonucleotides caused the same pattern of inhibition as SR141716A. This provides more definitive evidence for the involvement of CB1 receptors in MAP kinase activation and suggests that anandamide may also activate MAP kinase via an additional, CB1 receptor-independent, SR141716A-resistant mechanism. The MAP kinase activation by anandamide in ECV304 cells requires genistein-sensitive tyrosine kinases and protein kinase C (PKC), and anandamide also activates p38 kinase and c-Jun kinase. These findings indicate that CB1 receptors located in human vascular endothelium are functionally coupled to the MAP kinase cascade. Activation of protein kinase cascades by anandamide may be involved in the modulation of endothelial cell growth and proliferation. PMID:10698714

  18. Functional interactions between endogenous cannabinoid and opioid systems: focus on alcohol, genetics and drug-addicted behaviors.

    PubMed

    López-Moreno, J A; López-Jiménez, A; Gorriti, M A; de Fonseca, F Rodríguez

    2010-04-01

    Although the first studies regarding the endogenous opioid system and addiction were published during the 1940s, addiction and cannabinoids were not addressed until the 1970s. Currently, the number of opioid addiction studies indexed in PubMed-Medline is 16 times greater than the number of cannabinoid addiction reports. More recently, functional interactions have been demonstrated between the endogenous cannabinoid and opioid systems. For example, the cannabinoid brain receptor type 1 (CB1) and mu opioid receptor type 1 (MOR1) co-localize in the same presynaptic nerve terminals and signal through a common receptor-mediated G-protein pathway. Here, we review a great variety of behavioral models of drug addiction and alcohol-related behaviors. We also include data providing clear evidence that activation of the cannabinoid and opioid endogenous systems via WIN 55,512-2 (0.4-10 mg/kg) and morphine (1.0-10 mg/kg), respectively, produces similar levels of relapse to alcohol in operant alcohol self-administration tasks. Finally, we discuss genetic studies that reveal significant associations between polymorphisms in MOR1 and CB1 receptors and drug addiction. For example, the SNP A118G, which changes the amino acid aspartate to asparagine in the MOR1 gene, is highly associated with altered opioid system function. The presence of a microsatellite polymorphism of an (AAT)n triplet near the CB1 gene is associated with drug addiction phenotypes. But, studies exploring haplotypes with regard to both systems, however, are lacking.

  19. Multiple sleep alterations in mice lacking cannabinoid type 1 receptors.

    PubMed

    Silvani, Alessandro; Berteotti, Chiara; Bastianini, Stefano; Lo Martire, Viviana; Mazza, Roberta; Pagotto, Uberto; Quarta, Carmelo; Zoccoli, Giovanna

    2014-01-01

    Cannabinoid type 1 (CB1) receptors are highly expressed in the brain and play a role in behavior control. Endogenous cannabinoid signaling is modulated by high-fat diet (HFD). We investigated the consequences of congenital lack of CB1 receptors on sleep in mice fed standard diet (SD) and HFD. CB1 cannabinoid receptor knock-out (KO) and wild-type (WT) mice were fed SD or HFD for 4 months (n = 9-10 per group). Mice were instrumented with electroencephalographic (EEG) and electromyographic electrodes. Recordings were performed during baseline (48 hours), sleep deprivation (gentle handling, 6 hours), sleep recovery (18 hours), and after cage switch (insomnia model paradigm, 6 hours). We found multiple significant effects of genotype on sleep. In particular, KO spent more time awake and less time in non-rapid-eye-movement sleep (NREMS) and rapid-eye-movement sleep (REMS) than WT during the dark (active) period but not during the light (rest) period, enhancing the day-night variation of wake-sleep amounts. KO had slower EEG theta rhythm during REMS. REMS homeostasis after sleep deprivation was less effective in KO than in WT. Finally, KO habituated more rapidly to the arousing effect of the cage-switch test than WT. We did not find any significant effects of diet or of diet x genotype interaction on sleep. The occurrence of multiple sleep alterations in KO indicates important roles of CB1 cannabinoid receptors in limiting arousal during the active period of the day, in sleep regulation, and in sleep EEG in mice.

  20. Pharmacological and molecular characterization of a dorsal root ganglion cell line expressing cannabinoid CB(1) and CB(2) receptors.

    PubMed

    Fan, Yihong; Hooker, Bradley A; Garrison, Tiffany Runyan; El-Kouhen, Odile F; Idler, Kenneth B; Holley-Shanks, Rhonda R; Meyer, Michael D; Yao, Betty Bei

    2011-06-01

    The behavioral effects evoked by cannabinoids are primarily mediated by the CB(1) and CB(2) cannabinoid receptor subtypes. In vitro pharmacology of cannabinoid receptors has been elucidated using recombinant expression systems expressing either CB(1) or CB(2) receptors, with limited characterization in native cell lines endogenously expressing both CB(1) and CB(2) receptors. In the current study, we report the molecular and pharmacological characterization of the F-11 cell line, a hybridoma of rat dorsal root ganglion neurons and mouse neuroblastoma (N18TG2) cells, reported to endogenously express both cannabinoid receptors. The present study revealed that both receptors are of mouse origin in F-11 cells, and describes the relative gene expression levels between the two receptors. Pharmacological characterization of the F-11 cell line using cannabinoid agonists and antagonists indicated that the functional responses to these cannabinoid ligands are mainly mediated by CB(1) receptors. The non-selective cannabinoid ligands CP 55,940 and WIN 55212-2 are potent agonists and their efficacies in adenylate cyclase and MAPK assays are inhibited by the CB(1) selective antagonist SR141716A (SR1), but not by the CB(2) selective antagonist SR144528 (SR2). The endocannabinoid ligand 2AG, although not active in adenylate cyclase assays, was a potent activator of MAPK signaling in F-11 cells. The analysis of CB(1) and CB(2) receptor gene expression and the characterization of cannabinoid receptor pharmacology in the F-11 cell line demonstrate that it can be used as a tool for interrogating the endogenous signal transduction of cannabinoid receptor subtypes.

  1. Targeted modulators of the endogenous cannabinoid system: future medications to treat addiction disorders and obesity.

    PubMed

    Janero, David R; Makriyannis, Alexandros

    2007-10-01

    The endogenous endocannabinoid system encompasses a family of natural signaling lipids ("endocannabinoids") functionally related to (9)-tetrahydrocannabinol, the psychoactive ingredient of marijuana (cannabis), along with proteins that modulate the endocannabinoids, including enzymes, transporters, and receptors. The endocannabinoid system's ubiquitous regulatory actions in health and disease underscore its importance to mammalian (patho)physiology and suggest discrete targets through which it may be modulated for therapeutic gain. Medications based on the endocannabinoid system are an important focus of contemporary translational research, particularly with respect to substance abuse and obesity, two prevalent disorders with a pathogenic component of endocannabinoid system hyperactivity. Pressing health care needs have made the rational design of targeted CB1 cannabinoid-receptor modulators a promising route to future medications with significant therapeutic impact against psychobehavioral and metabolic disturbances having a reward-supported appetitive component.

  2. A runner’s high depends on cannabinoid receptors in mice

    PubMed Central

    Fuss, Johannes; Steinle, Jörg; Bindila, Laura; Auer, Matthias K.; Kirchherr, Hartmut; Lutz, Beat; Gass, Peter

    2015-01-01

    Exercise is rewarding, and long-distance runners have described a runner’s high as a sudden pleasant feeling of euphoria, anxiolysis, sedation, and analgesia. A popular belief has been that endogenous endorphins mediate these beneficial effects. However, running exercise increases blood levels of both β-endorphin (an opioid) and anandamide (an endocannabinoid). Using a combination of pharmacologic, molecular genetic, and behavioral studies in mice, we demonstrate that cannabinoid receptors mediate acute anxiolysis and analgesia after running. We show that anxiolysis depends on intact cannabinoid receptor 1 (CB1) receptors on forebrain GABAergic neurons and pain reduction on activation of peripheral CB1 and CB2 receptors. We thus demonstrate that the endocannabinoid system is crucial for two main aspects of a runner's high. Sedation, in contrast, was not influenced by cannabinoid or opioid receptor blockage, and euphoria cannot be studied in mouse models. PMID:26438875

  3. Effects of cannabinoids and their receptors on viral infections.

    PubMed

    Tahamtan, Alireza; Tavakoli-Yaraki, Masoumeh; Rygiel, Tomasz P; Mokhtari-Azad, Talat; Salimi, Vahid

    2016-01-01

    Cannabinoids, the active ingredient in marijuana, and their derivatives have received remarkable attention in the last two decades because they can affect tumor growth and metastasis. There is a large body of evidence from in vivo and in vitro models showing that cannabinoids and their receptors influence the immune system, viral pathogenesis, and viral replication. The present study reviews current insights into the role of cannabinoids and their receptors on viral infections. The results reported here indicate that cannabinoids and their receptors have different sequels for viral infection. Although activation or inhibition of cannabinoid receptors in the majority of viral infections are proper targets for development of safe and effective treatments, caution is required before using pharmaceutical cannabinoids as a treatment agent for patients with viral infections.

  4. 3'-functionalized adamantyl cannabinoid receptor probes.

    PubMed

    Ogawa, Go; Tius, Marcus A; Zhou, Han; Nikas, Spyros P; Halikhedkar, Aneetha; Mallipeddi, Srikrishnan; Makriyannis, Alexandros

    2015-04-09

    The aliphatic side chain plays a pivotal role in determining the cannabinergic potency of tricyclic classical cannabinoids, and we have previously shown that this chain could be substituted successfully by adamantyl or other polycyclic groups. In an effort to explore the pharmacophoric features of these conformationally fixed groups, we have synthesized a series of analogues in which the C3 position is substituted directly with an adamantyl group bearing functionality at one of the tertiary carbon atoms. These substituents included the electrophilic isothiocyanate and photoactivatable azido groups, both of which are capable of covalent attachment with the target protein. Our results show that substitution at the 3'-adamantyl position can lead to ligands with improved affinities and CB1/CB2 selectivities. Our work has also led to the development of two successful covalent probes with high affinities for both cannabinoid receptors, namely, the electrophilic isothiocyanate AM994 and the photoactivatable aliphatic azido AM993 analogues.

  5. The discovery of a cannabinoid receptor

    SciTech Connect

    Devane, W.A.

    1989-01-01

    A tritiated form of CP-55,940, a Pfizer cannabinoid analog that is 20- to 100-fold more potent than {Delta}{sup 9}-tetrahydrocannabinol in various in vivo and in vitro models of cannabimimetric activity, was used as the tool with which to probe for a cannabinoid receptor in rat cortical membranes. The bound and free ligand were successfully separated using a centrifugation assay. Specific binding was saturable, rapidly attained, and completely reversible. The K{sub D}'s derived from kinetic analysis of binding agreed well with the K{sub D}'s derived from saturation and displacement analysis. The ({sup 3}H)CP-55,940 binding site exhibited high affinity with a K{sub D} of 68 pM as determined by LIGAND analysis of homologous displacement studies. The ability of other cannabinoid drugs to displace ({sup 3}H)CP-55,940 binding correlated well with the potency of these drugs in in vivo and in vitro models of cannabimimetic activity. The K{sub i} of {Delta}{sup 9}-THC was 1.6 nM. Cannabidiol and cannabigerol, which both lack psychoactivity in man, displaced specific binding by less than 50% at 1 {mu}M.

  6. The endogenous cannabinoid system affects energy balance via central orexigenic drive and peripheral lipogenesis

    PubMed Central

    Cota, Daniela; Marsicano, Giovanni; Tschöp, Matthias; Grübler, Yvonne; Flachskamm, Cornelia; Schubert, Mirjam; Auer, Dorothee; Yassouridis, Alexander; Thöne-Reineke, Christa; Ortmann, Sylvia; Tomassoni, Federica; Cervino, Cristina; Nisoli, Enzo; Linthorst, Astrid C.E.; Pasquali, Renato; Lutz, Beat; Stalla, Günter K.; Pagotto, Uberto

    2003-01-01

    The cannabinoid receptor type 1 (CB1) and its endogenous ligands, the endocannabinoids, are involved in the regulation of food intake. Here we show that the lack of CB1 in mice with a disrupted CB1 gene causes hypophagia and leanness. As compared with WT (CB1+/+) littermates, mice lacking CB1 (CB1–/–) exhibited reduced spontaneous caloric intake and, as a consequence of reduced total fat mass, decreased body weight. In young CB1–/– mice, the lean phenotype is predominantly caused by decreased caloric intake, whereas in adult CB1–/– mice, metabolic factors appear to contribute to the lean phenotype. No significant differences between genotypes were detected regarding locomotor activity, body temperature, or energy expenditure. Hypothalamic CB1 mRNA was found to be coexpressed with neuropeptides known to modulate food intake, such as corticotropin-releasing hormone (CRH), cocaine-amphetamine–regulated transcript (CART), melanin-concentrating hormone (MCH), and prepro-orexin, indicating a possible role for endocannabinoid receptors within central networks governing appetite. CB1–/– mice showed significantly increased CRH mRNA levels in the paraventricular nucleus and reduced CART mRNA levels in the dorsomedial and lateral hypothalamic areas. CB1 was also detected in epidydimal mouse adipocytes, and CB1-specific activation enhanced lipogenesis in primary adipocyte cultures. Our results indicate that the cannabinoid system is an essential endogenous regulator of energy homeostasis via central orexigenic as well as peripheral lipogenic mechanisms and might therefore represent a promising target to treat diseases characterized by impaired energy balance. PMID:12897210

  7. CB2 Cannabinoid Receptor As Potential Target against Alzheimer's Disease

    PubMed Central

    Aso, Ester; Ferrer, Isidro

    2016-01-01

    The CB2 receptor is one of the components of the endogenous cannabinoid system, a complex network of signaling molecules and receptors involved in the homeostatic control of several physiological functions. Accumulated evidence suggests a role for CB2 receptors in Alzheimer's disease (AD) and indicates their potential as a therapeutic target against this neurodegenerative disease. Levels of CB2 receptors are significantly increased in post-mortem AD brains, mainly in microglia surrounding senile plaques, and their expression levels correlate with the amounts of Aβ42 and β-amyloid plaque deposition. Moreover, several studies on animal models of AD have demonstrated that specific CB2 receptor agonists, which are devoid of psychoactive effects, reduce AD-like pathology, resulting in attenuation of the inflammation associated with the disease but also modulating Aβ and tau aberrant processing, among other effects. CB2 receptor activation also improves cognitive impairment in animal models of AD. This review discusses available data regarding the role of CB2 receptors in AD and the potential usefulness of specific agonists of these receptors against AD. PMID:27303261

  8. Physiological and behavioural effects of the endogenous cannabinoid, arachidonylethanolamide (anandamide), in the rat.

    PubMed Central

    Stein, E. A.; Fuller, S. A.; Edgemond, W. S.; Campbell, W. B.

    1996-01-01

    1. Arachidonylethanolamide (AEA; anandamide) has been isolated from mammalian brain and found to bind to, and is thought to be, an endogenous ligand for the cannabinoid receptor. In order to understand better its behavioural and physiological properties, we have examined its acute effects in unanaesthetized freely behaving rats. 2. Intravenous AEA caused dose-related decreases in locomotor behaviour, a pronounced hyperreflexia, and a moderate antinociceptive state. At doses between 3 and 30 mg kg-1, a dose-dependent hypothermia and profound, time-dependent cardiovascular changes were also observed. 3. An immediate bradycardia exceeding 50% was seen within 10-15 s of administration and lasted up to 11 min following the highest dose of the drug. In contrast, the change in mean arterial pressure was biphasic: an immediate 20% decrease in mean arterial pressure followed by a significant increase in blood pressure that lasted about 13 min after the highest dose. 4. These data demonstrate that AEA in the unanaesthetized rat exerts behavioural and physiological effects generally similar to those seen following natural cannabinoids and synthetic cannabimimetic agents and suggests a role for AEA in regulation of various physiological processes. Images Figure 2 Figure 4 Figure 5 Figure 7 PMID:8872363

  9. International Union of Basic and Clinical Pharmacology. LXXIX. Cannabinoid Receptors and Their Ligands: Beyond CB1 and CB2

    PubMed Central

    Howlett, A. C.; Abood, M. E.; Alexander, S. P. H.; Di Marzo, V.; Elphick, M. R.; Greasley, P. J.; Hansen, H. S.; Kunos, G.; Mackie, K.; Mechoulam, R.; Ross, R. A.

    2010-01-01

    There are at least two types of cannabinoid receptors (CB1 and CB2). Ligands activating these G protein-coupled receptors (GPCRs) include the phytocannabinoid Δ9-tetrahydrocannabinol, numerous synthetic compounds, and endogenous compounds known as endocannabinoids. Cannabinoid receptor antagonists have also been developed. Some of these ligands activate or block one type of cannabinoid receptor more potently than the other type. This review summarizes current data indicating the extent to which cannabinoid receptor ligands undergo orthosteric or allosteric interactions with non-CB1, non-CB2 established GPCRs, deorphanized receptors such as GPR55, ligand-gated ion channels, transient receptor potential (TRP) channels, and other ion channels or peroxisome proliferator-activated nuclear receptors. From these data, it is clear that some ligands that interact similarly with CB1 and/or CB2 receptors are likely to display significantly different pharmacological profiles. The review also lists some criteria that any novel “CB3” cannabinoid receptor or channel should fulfil and concludes that these criteria are not currently met by any non-CB1, non-CB2 pharmacological receptor or channel. However, it does identify certain pharmacological targets that should be investigated further as potential CB3 receptors or channels. These include TRP vanilloid 1, which possibly functions as an ionotropic cannabinoid receptor under physiological and/or pathological conditions, and some deorphanized GPCRs. Also discussed are 1) the ability of CB1 receptors to form heteromeric complexes with certain other GPCRs, 2) phylogenetic relationships that exist between CB1/CB2 receptors and other GPCRs, 3) evidence for the existence of several as-yet-uncharacterized non-CB1, non-CB2 cannabinoid receptors; and 4) current cannabinoid receptor nomenclature. PMID:21079038

  10. International Union of Basic and Clinical Pharmacology. LXXIX. Cannabinoid receptors and their ligands: beyond CB₁ and CB₂.

    PubMed

    Pertwee, R G; Howlett, A C; Abood, M E; Alexander, S P H; Di Marzo, V; Elphick, M R; Greasley, P J; Hansen, H S; Kunos, G; Mackie, K; Mechoulam, R; Ross, R A

    2010-12-01

    There are at least two types of cannabinoid receptors (CB(1) and CB(2)). Ligands activating these G protein-coupled receptors (GPCRs) include the phytocannabinoid Δ(9)-tetrahydrocannabinol, numerous synthetic compounds, and endogenous compounds known as endocannabinoids. Cannabinoid receptor antagonists have also been developed. Some of these ligands activate or block one type of cannabinoid receptor more potently than the other type. This review summarizes current data indicating the extent to which cannabinoid receptor ligands undergo orthosteric or allosteric interactions with non-CB(1), non-CB(2) established GPCRs, deorphanized receptors such as GPR55, ligand-gated ion channels, transient receptor potential (TRP) channels, and other ion channels or peroxisome proliferator-activated nuclear receptors. From these data, it is clear that some ligands that interact similarly with CB(1) and/or CB(2) receptors are likely to display significantly different pharmacological profiles. The review also lists some criteria that any novel "CB(3)" cannabinoid receptor or channel should fulfil and concludes that these criteria are not currently met by any non-CB(1), non-CB(2) pharmacological receptor or channel. However, it does identify certain pharmacological targets that should be investigated further as potential CB(3) receptors or channels. These include TRP vanilloid 1, which possibly functions as an ionotropic cannabinoid receptor under physiological and/or pathological conditions, and some deorphanized GPCRs. Also discussed are 1) the ability of CB(1) receptors to form heteromeric complexes with certain other GPCRs, 2) phylogenetic relationships that exist between CB(1)/CB(2) receptors and other GPCRs, 3) evidence for the existence of several as-yet-uncharacterized non-CB(1), non-CB(2) cannabinoid receptors; and 4) current cannabinoid receptor nomenclature.

  11. [Drug discrimination properties and cytotoxicity of the cannabinoid receptor ligands].

    PubMed

    Tomiyama, Ken-ichi; Funada, Masahiko

    2012-06-01

    The worldwide distribution of smokable herbal mixtures called "Spice" that contain synthetic cannabinoids with a pharmacological activity similar to delta 9-tetrahydrocannabinol (delta 9-THC) has been reported. The synthetic cannabinoids induce behavior and have biochemical properties similar to naturally occurring cannabinoids such as delta 9-THC. In drug discrimination procedures, animal behavior is differentially reinforced depending on the presence or absence of specific drug stimuli. This review seeks to establish an animal model to serve as a discriminative stimulus of the synthetic cannabinoids, to determine whether this discriminative stimulus is identical to that of delta 9-THC. Much data have been obtained in drug discrimination experiments with various synthetic cannabinoids. In the discriminative study, synthetic cannabinoids such as CP-55,940 and WIN-55,212-2 were substituted for delta 9-THC in rats trained to discriminate delta 9-THC from the vehicle. These discriminative effects of synthetic cannabinoids were antagonized by CB1 antagonist SR-141,716A. The discriminative effects of synthetic cannabinoids may overlap with the delta 9-THC cue mediated by CB1 receptors. In in vitro study using NG 108-15 cell lines, synthetic cannabinoids have produced strong cytotoxicities that were suppressed by pretreatment with the CB1 receptor antagonist. Furthermore, pretreatment with caspase inhibitors suppressed these synthetic-cannabinoid-induced cytotoxicities in NG 108-15 cells. These findings indicate that the cytotoxicity of synthetic cannabinoids towards NG 108-15 cells is mediated by the CB1 receptors and further suggest that caspase cascades may play an important role in the cytotoxicities induced by these synthetic cannabinoids. In conclusion, synthetic cannabinoid abuse could be a health hazard for humans.

  12. Emerging strategies for exploiting cannabinoid receptor agonists as medicines.

    PubMed

    Pertwee, Roger G

    2009-02-01

    Medicines that activate cannabinoid CB(1) and CB(2) receptor are already in the clinic. These are Cesamet (nabilone), Marinol (dronabinol; Delta(9)-tetrahydrocannabinol) and Sativex (Delta(9)-tetrahydrocannabinol with cannabidiol). The first two of these medicines can be prescribed to reduce chemotherapy-induced nausea and vomiting. Marinol can also be prescribed to stimulate appetite, while Sativex is prescribed for the symptomatic relief of neuropathic pain in adults with multiple sclerosis and as an adjunctive analgesic treatment for adult patients with advanced cancer. One challenge now is to identify additional therapeutic targets for cannabinoid receptor agonists, and a number of potential clinical applications for such agonists are mentioned in this review. A second challenge is to develop strategies that will improve the efficacy and/or the benefit-to-risk ratio of a cannabinoid receptor agonist. This review focuses on five strategies that have the potential to meet either or both of these objectives. These are strategies that involve: (i) targeting cannabinoid receptors located outside the blood-brain barrier; (ii) targeting cannabinoid receptors expressed by a particular tissue; (iii) targeting up-regulated cannabinoid receptors; (iv) targeting cannabinoid CB(2) receptors; or (v) 'multi-targeting'. Preclinical data that justify additional research directed at evaluating the clinical importance of each of these strategies are also discussed.

  13. Emerging strategies for exploiting cannabinoid receptor agonists as medicines

    PubMed Central

    Pertwee, Roger G

    2009-01-01

    Medicines that activate cannabinoid CB1 and CB2 receptor are already in the clinic. These are Cesamet® (nabilone), Marinol® (dronabinol; Δ9-tetrahydrocannabinol) and Sativex® (Δ9-tetrahydrocannabinol with cannabidiol). The first two of these medicines can be prescribed to reduce chemotherapy-induced nausea and vomiting. Marinol® can also be prescribed to stimulate appetite, while Sativex® is prescribed for the symptomatic relief of neuropathic pain in adults with multiple sclerosis and as an adjunctive analgesic treatment for adult patients with advanced cancer. One challenge now is to identify additional therapeutic targets for cannabinoid receptor agonists, and a number of potential clinical applications for such agonists are mentioned in this review. A second challenge is to develop strategies that will improve the efficacy and/or the benefit-to-risk ratio of a cannabinoid receptor agonist. This review focuses on five strategies that have the potential to meet either or both of these objectives. These are strategies that involve: (i) targeting cannabinoid receptors located outside the blood-brain barrier; (ii) targeting cannabinoid receptors expressed by a particular tissue; (iii) targeting up-regulated cannabinoid receptors; (iv) targeting cannabinoid CB2 receptors; or (v) ‘multi-targeting’. Preclinical data that justify additional research directed at evaluating the clinical importance of each of these strategies are also discussed. PMID:19226257

  14. Altered gene expression and functional activity of opioid receptors in the cerebellum of CB1 cannabinoid receptor knockout mice after acute treatments with cannabinoids.

    PubMed

    Páldyová, Estera; Bereczki, E; Sántha, M; Wenger, T; Borsodi, Anna; Benyhe, S

    2007-01-01

    Numerous studies have shown functional links between the cannabinoid and opioid systems. The goal of this study was to evaluate whether acute treatments by endogenous cannabinoid agonist, selective CB1 or CB2 receptor antagonists modulate the expression of mu- (MOR) and delta- (DOR) opioid receptor mRNA levels and functional activity in the cerebellum of transgenic mice deficient in the CB1 type of cannabis receptors. We examined the effect of noladin ether (endogenous cannabinoid agonist) pretreatment on MOR and DOR mRNA expression by using reverse transcription and real-time polimerase chain reaction (PCR) and the ability of subsequent application of the opioid agonists to activate G-proteins, as measured by [35S]GTPgammaS binding, in wild-type (CB1+/+) and CB1 cannabinoid receptor deficient (CB1-/-, 'knockout', K.O.) mice. The acute administration of noladin ether markedly reduced MOR-mediated G-protein activation and caused a significant increase in the level of MOR mRNAs in the cerebella of wildtype, but not in the CB1-/- mice. No significant differences were observed in DOR functional activity and mRNA expression in wild-type animals. In CB1-/- mice the expression of DOR mRNA increased after noladin ether treatment, but no changes were found in DOR functional activity. In addition, Rimonabant (selective central cannabinoid CB1 receptor antagonist) and SR144528 (selective peripheral cannabinoid CB2 receptor antagonist) caused significant potentiation in MOR functional activity in the wild-type animals, whereas DOR mediated G-protein activation was increased in the CB1-/- mice. In contrast, Rimonabant and SR144528 decreased the MOR and DOR mRNA expressions in both CB1+/+ and CB1-/- mice. Taken together, these results indicate that acute treatment with cannabinoids causes alterations in MOR and DOR mRNA expression and functional activity in the cerebella of wild-type and CB1 knockout mice indicating indirect interactions between these two signaling systems.

  15. Ontogenetic development of cannabinoid receptor expression and signal transduction functionality in the human brain.

    PubMed

    Mato, Susana; Del Olmo, Elena; Pazos, Angel

    2003-05-01

    Previous evidence suggests that the endogenous cannabinoid system emerges relatively early during brain development in the rat. However, the pre- and postnatal pattern of appearance of CB1 cannabinoid receptors in humans has not been analysed in detail. Furthermore, there is a complete lack of information about the functional ability of these proteins to activate signal transduction mechanisms during human development. In the present study we have explored CB1 receptor expression throughout the different areas of the developing human brain by [3H]CP55 940 autoradiography. We have also assessed CB1 functional coupling to G proteins during brain development by agonist-stimulated [35S]GTPgammaS autoradiography in the same cases. Our results indicate a significant density of cannabinoid receptors at 19 weeks' gestation in the same areas that contain these receptors in the adult human brain. Autoradiographic levels of CB1 receptors in these structures seem to increase progressively from early prenatal stages to adulthood. Interestingly, high densities of cannabinoid receptors have also been detected during prenatal development in fibre-enriched areas that are practically devoid of them in the adult brain. In parallel with these data, we have found that brain cannabinoid receptors are functionally coupled to signal transduction mechanisms from early prenatal stages. This early pattern of expression of functionally active cannabinoid receptors, along with the transient and atypical localization of these proteins in white matter areas during the prenatal stages, suggest an specific role of the endocannabinoid system in the events related to human neural development.

  16. Anandamide (arachidonylethanolamide), a brain cannabinoid receptor agonist, reduces sperm fertilizing capacity in sea urchins by inhibiting the acrosome reaction.

    PubMed Central

    Schuel, H; Goldstein, E; Mechoulam, R; Zimmerman, A M; Zimmerman, S

    1994-01-01

    Anandamide (arachidonylethanolamide) is an endogenous cannabinoid receptor agonist in mammalian brain. Sea urchin sperm contain a high-affinity cannabinoid receptor similar to the cannabinoid receptor in mammalian brain. (-)-delta 9-Tetrahydrocannabinol (THC), the primary psychoactive cannabinoid in marihuana, reduces the fertilizing capacity of sea urchin sperm by blocking the acrosome reaction that normally is stimulated by a specific ligand in the egg's jelly coat. We now report that anandamide produces effects similar to those previously obtained with THC in Strongylocentrotus purpuratus in reducing sperm fertilizing capacity and inhibiting the egg jelly-stimulated acrosome reaction. Arachidonic acid does not inhibit the acrosome reaction under similar conditions. The adverse effects of anandamide on sperm fertilizing capacity and the acrosome reaction are reversible. The receptivity of unfertilized eggs to sperm and sperm motility are not impaired by anandamide. Under conditions where anandamide completely blocks the egg jelly-stimulated acrosome reaction, it does not inhibit the acrosome reaction artificially initiated by ionomycin, which promotes Ca2+ influx, and nigericin, which activates K+ channels in sperm. These findings provide additional evidence that the cannabinoid receptor in sperm plays a role in blocking the acrosome reaction, indicate that anandamide or a related molecule may be the natural ligand for the cannabinoid receptor in sea urchin sperm, and suggest that binding of anandamide to the cannabinoid receptor modulates stimulus-secretion-coupling in sperm by affecting an event prior to ion channel opening. PMID:8052642

  17. Mutation of putative GRK phosphorylation sites in the cannabinoid receptor 1 (CB1R) confers resistance to cannabinoid tolerance and hypersensitivity to cannabinoids in mice.

    PubMed

    Morgan, Daniel J; Davis, Brian J; Kearn, Chris S; Marcus, David; Cook, Alex J; Wager-Miller, Jim; Straiker, Alex; Myoga, Michael H; Karduck, Jeffrey; Leishman, Emma; Sim-Selley, Laura J; Czyzyk, Traci A; Bradshaw, Heather B; Selley, Dana E; Mackie, Ken

    2014-04-09

    For many G-protein-coupled receptors (GPCRs), including cannabinoid receptor 1 (CB1R), desensitization has been proposed as a principal mechanism driving initial tolerance to agonists. GPCR desensitization typically requires phosphorylation by a G-protein-coupled receptor kinase (GRK) and interaction of the phosphorylated receptor with an arrestin. In simple model systems, CB1R is desensitized by GRK phosphorylation at two serine residues (S426 and S430). However, the role of these serine residues in tolerance and dependence for cannabinoids in vivo was unclear. Therefore, we generated mice where S426 and S430 were mutated to nonphosphorylatable alanines (S426A/S430A). S426A/S430A mutant mice were more sensitive to acutely administered delta-9-tetrahydrocannabinol (Δ(9)-THC), have delayed tolerance to Δ(9)-THC, and showed increased dependence for Δ(9)-THC. S426A/S430A mutants also showed increased responses to elevated levels of endogenous cannabinoids. CB1R desensitization in the periaqueductal gray and spinal cord following 7 d of treatment with Δ(9)-THC was absent in S426A/S430A mutants. Δ(9)-THC-induced downregulation of CB1R in the spinal cord was also absent in S426A/S430A mutants. Cultured autaptic hippocampal neurons from S426A/S430A mice showed enhanced endocannabinoid-mediated depolarization-induced suppression of excitation (DSE) and reduced agonist-mediated desensitization of DSE. These results indicate that S426 and S430 play major roles in the acute response to, tolerance to, and dependence on cannabinoids. Additionally, S426A/S430A mice are a novel model for studying pathophysiological processes thought to involve excessive endocannabinoid signaling such as drug addiction and metabolic disease. These mice also validate the approach of mutating GRK phosphorylation sites involved in desensitization as a general means to confer exaggerated signaling to GPCRs in vivo.

  18. Identification of cannabinoid type 1 receptor in dog hair follicles.

    PubMed

    Mercati, Francesca; Dall'Aglio, Cecilia; Pascucci, Luisa; Boiti, Cristiano; Ceccarelli, Piero

    2012-01-01

    In veterinary medicine, there is an increasing interest in the study of the endo-cannabinoid system and the possible use of the cannabinoids for the treatment of several diseases. Cannabinoid receptors (CB) are widely distributed in human and laboratory animal tissues, justifying the involvement of the endo-cannabinoid system in a great number of metabolic ways. Since there are no data regarding cannabinoid receptors in hair follicles of domestic animals, we investigated the presence and localization of CB1 receptor in dog hair follicles. By using a goat anti-CB1 polyclonal antibody, we observed CB1 receptor in the proximal part of both primary and secondary hair follicles. Staining was localized in the inner root sheath cells. We suppose that the endo-cannabinoid system is involved in the molecular mechanisms regulating hair follicle activity in dog. The identification of CB1 receptor at the level of the inner root sheath may help in the understanding of hair follicle biology and the possibility that cannabinoid molecules could be considered as suitable therapeutic tools in dog.

  19. Endogenous and Synthetic Cannabinoids as Therapeutics in Retinal Disease

    PubMed Central

    Kokona, Despina; Georgiou, Panagiota-Christina; Kounenidakis, Mihalis; Kiagiadaki, Foteini; Thermos, Kyriaki

    2016-01-01

    The functional significance of cannabinoids in ocular physiology and disease has been reported some decades ago. In the early 1970s, subjects who smoked Cannabis sativa developed lower intraocular pressure (IOP). This led to the isolation of phytocannabinoids from this plant and the study of their therapeutic effects in glaucoma. The main treatment of this disease to date involves the administration of drugs mediating either the decrease of aqueous humour synthesis or the increase of its outflow and thus reduces IOP. However, the reduction of IOP is not sufficient to prevent visual field loss. Retinal diseases, such as glaucoma and diabetic retinopathy, have been defined as neurodegenerative diseases and characterized by ischemia-induced excitotoxicity and loss of retinal neurons. Therefore, new therapeutic strategies must be applied in order to target retinal cell death, reduction of visual acuity, and blindness. The aim of the present review is to address the neuroprotective and therapeutic potential of cannabinoids in retinal disease. PMID:26881135

  20. Toxicological profiles of selected synthetic cannabinoids showing high binding affinities to the cannabinoid receptor subtype CB₁.

    PubMed

    Koller, Verena J; Zlabinger, Gerhard J; Auwärter, Volker; Fuchs, Sabine; Knasmueller, Siegfried

    2013-07-01

    Products containing synthetic cannabinoids are consumed as a surrogate for marihuana due to their non-detectability with commonly used drug tests and their strong cannabimimetic effects. Because data concerning their toxicological properties are scarce, the cytotoxic, genotoxic, immunomodulatory, and hormonal activities of four naphthoylindole compounds (JWH-018, JWH-073, JWH-122 and JWH-210) and of one benzoylindole (AM-694) were studied in human cell lines and primary cells; tetrahydrocannabinol was included as the classical non-endogenous cannabinoid receptor ligand. All compounds induced damage to the cell membranes of buccal (TR146) and breast (MCF-7) derived cells at concentrations of ≥75-100 μM. No cytotoxic responses were seen in other assays which reflect mitochondrial damage, protein synthesis, and lysosomal activities. JWH-073 and JWH-122 induced DNA migration in buccal and liver cells (HepG2) in single cell gel electrophoresis assays, while JWH-210 was only in the latter cell line active. No estrogenic activities were detected in bone marrow cells (U2-OS), but all compounds caused anti-estrogenic effects at levels between 2.1 and 23.0 μM. Furthermore, no impact on cytokine release (i.e., on IL-10, IL-6, IL-12/23p40 and TNFα levels) was seen in LPS-stimulated human PBMCs, except with JWH-210 and JWH-122 which caused a decrease of TNFα and IL-12/23p40. All toxic effects were observed with concentrations higher than those expected in body fluids of users. Since genotoxic effects are in general linear over a wide concentration range and the exposure levels may be higher in epithelial cells than [corrected] in serum, further experimental work is required to find out if DNA damage takes place in drug users.

  1. Cannabinoid receptors and TRPA1 on neuroprotection in a model of retinal ischemia.

    PubMed

    Araújo, D S M; Miya-Coreixas, V S; Pandolfo, P; Calaza, K C

    2017-01-01

    Retinal ischemia is a pathological event present in several retinopathies such as diabetic retinopathy and glaucoma, leading to partial or full blindness with no effective treatment available. Since synthetic and endogenous cannabinoids have been studied as modulators of ischemic events in the central nervous system (CNS), the present study aimed to investigate the involvement of cannabinoid system in the cell death induced by ischemia in an avascular (chick) retina. We observed that chick retinal treatment with a combination of WIN 55212-2 and cannabinoid receptor antagonists (either AM251/O-2050 or AM630) decreased the release of lactate dehydrogenase (LDH) induced by retinal ischemia in an oxygen and glucose deprivation (OGD) model. Further, the increased availability of endocannabinoids together with cannabinoid receptor antagonists also had a neuroprotective effect. Surprisingly, retinal exposure to any of these drugs alone did not prevent the release of LDH stimulated by OGD. Since cannabinoids may also activate transient receptor potential (TRP) channels, we investigated the involvement of TRPA1 receptors (TRPA1) in retinal cell death induced by ischemic events. We demonstrated the presence of TRPA1 in the chick retina, and observed an increase in TRPA1 content after OGD, both by western blot and immunohistochemistry. In addition, the selective activation of TRPA1 by mustard oil (MO) did not worsen retinal LDH release induced by OGD, whereas the blockage of TRPA1 completely prevented the extravasation of cellular LDH in ischemic condition. Hence, these results show that during the ischemic event there is an augment of TRPA1, and activation of this receptor is important in cell death induction. The data also indicate that metabotropic cannabinoid receptors, both type 1 and 2, are not involved with the cell death found in the early stages of ischemia. Therefore, the study points to a potential role of TRPA1 as a target for neuroprotective approaches in retinal

  2. Genetic variability in the human cannabinoid receptor 1 is associated with resting state EEG theta power in humans.

    PubMed

    Heitland, I; Kenemans, J L; Böcker, K B E; Baas, J M P

    2014-11-01

    It has long been postulated that exogenous cannabinoids have a profound effect on human cognitive functioning. These cannabinoid effects are thought to depend, at least in parts, on alterations of phase-locking of local field potential neuronal firing. The latter can be measured as activity in the theta frequency band (4-7Hz) by electroencephalogram. Theta oscillations are supposed to serve as a mechanism in neural representations of behaviorally relevant information. However, it remains unknown whether variability in endogenous cannabinoid activity is involved in theta rhythms and therefore, may serve as an individual differences index of human cognitive functioning. To clarify this issue, we recorded resting state EEG activity in 164 healthy human subjects and extracted EEG power across frequency bands (δ, θ, α, and β). To assess variability in the endocannabinoid system, two genetic polymorphisms (rs1049353, rs2180619) within the cannabinoid receptor 1 (CB1) were determined in all participants. As expected, we observed significant effects of rs1049353 on EEG power in the theta band at frontal, central and parietal electrode regions. Crucially, these effects were specific for the theta band, with no effects on activity in the other frequency bands. Rs2180619 showed no significant associations with theta power after Bonferroni correction. Taken together, we provide novel evidence in humans showing that genetic variability in the cannabinoid receptor 1 is associated with resting state EEG power in the theta frequency band. This extends prior findings of exogenous cannabinoid effects on theta power to the endogenous cannabinoid system.

  3. Deletion of CB2 cannabinoid receptors reduces synaptic transmission and long-term potentiation in the mouse hippocampus.

    PubMed

    Li, Yong; Kim, Jimok

    2016-03-01

    The effects of cannabinoids are mostly mediated by two types of cannabinoid receptors--CB1 receptors in the nervous system and CB2 receptors in the immune system. However, CB2 cannabinoid receptors have recently been discovered in the brain and also implicated in neurophysiological functions. The deletion of CB2 receptors in mice induces long-term memory deficits and schizophrenia-like behaviors, implying that endogenous activity of CB2 receptors might be involved in neuropsychiatric effects. Little is known about the cellular mechanisms by which physiological activation of CB2 receptors modulates neuronal functions. We aimed to determine how deletion of CB2 receptors in mice affects synaptic transmission and plasticity. Electrophysiological and morphological studies indicated that CB2 receptor knockout resulted in decreases in excitatory synaptic transmission, long-term potentiation, and dendritic spine density in the hippocampus. Our data imply that endogenous activity of CB2 receptors might contribute to the maintenance of synaptic functions and the expression of normal long-term potentiation. This study provides insights into the role of CB2 cannabinoid receptors in regulating cognitive functions such as long-term memory.

  4. Expression of the cannabinoid receptor CB1 in distinct neuronal subpopulations in the adult mouse forebrain.

    PubMed

    Marsicano, G; Lutz, B

    1999-12-01

    Cannabinoids can modulate motor behaviour, learning and memory, cognition and pain perception. These effects correlate with the expression of the cannabinoid receptor 1 (CB1) and with the presence of endogenous cannabinoids in the brain. In trying to obtain further insights into the mechanisms underlying the modulatory effects of cannabinoids, CB1-positive neurons were determined in the murine forebrain at a single cell resolution. We performed a double in situ hybridization study to detect mRNA of CB1 in combination with mRNA of glutamic acid decarboxylase 65k, neuropeptide cholecystokinin (CCK), parvalbumin, calretinin and calbindin D28k, respectively. Our results revealed that CB1-expressing cells can be divided into distinct neuronal subpopulations. There is a clear distinction between neurons containing CB1 mRNA either at high levels or low levels. The majority of high CB1-expressing cells are GABAergic (gamma-aminobutyric acid) neurons belonging mainly to the cholecystokinin-positive and parvalbumin-negative type of interneurons (basket cells) and, to a lower extent, to the calbindin D28k-positive mid-proximal dendritic inhibitory interneurons. Only a fraction of low CB1-expressing cells is GABAergic. In the hippocampus, amygdala and entorhinal cortex area, CB1 mRNA is present at low but significant levels in many non-GABAergic cells that can be considered as projecting principal neurons. Thus, a complex mechanism appears to underlie the modulatory effects of cannabinoids. They might act on principal glutamatergic circuits as well as modulate local GABAergic inhibitory circuits. CB1 is very highly coexpressed with CCK. It is known that cannabinoids and CCK often have opposite effects on behaviour and physiology. Therefore, we suggest that a putative cross-talk between cannabinoids and CCK might exist and will be relevant to better understanding of physiology and pharmacology of the cannabinoid system.

  5. Cannabinoid receptor agonists modulate calcium channels in rat retinal Müller cells.

    PubMed

    Yang, W; Li, Q; Wang, S-Y; Gao, F; Qian, W-J; Li, F; Ji, M; Sun, X-H; Miao, Y; Wang, Z

    2016-01-28

    While activation of cannabinoid CB1 receptor (CB1R) regulates a variety of retinal neuronal functions by modulating ion channels in these cells, effect of activated cannabinoid receptors on Ca(2+) channels in retinal Müller cells is still largely unknown. In the present work we show that three subunits of T-type Ca(2+) channels, CaV3.1, CaV3.2 and CaV3.3, as well as one subunit of L-type Ca(2+) channels, CaV1.2, were expressed in rat Müller cells by immunofluorescent staining. Consistently, nimodipine- and mibefradil-sensitive Na(+) currents through L- and T-type Ca(2+) channels could be recorded electrophysiologically. The cannabinoid receptor agonist WIN55212-2 significantly suppressed Ca(2+) channel currents, mainly the T-type one, in acutely isolated rat Müller cells in a dose-dependent manner, with an IC50 of 3.98μM. The WIN55212-2 effect was not blocked by AM251/SR141716, specific CB1R antagonists. Similar suppression of the currents was observed when anandamide (AEA) and 2-arachidonoyl glycerol (2-AG), endogenous ligands of cannabinoid receptors, were applied. Moreover, even though CB2 receptors (CB2Rs) were expressed in rat Müller cells, the effects of WIN55212-2 and 2-AG on Ca(2+) channel currents were not blocked by AM630, a selective CB2R antagonist. However, the effect of AEA could be partially rescued by AM630. These results suggest that WIN55212-2 and 2-AG receptor-independently suppressed the Ca(2+) channel currents in Müller cells, while AEA suppressed the currents partially through CB2Rs. The existence of receptor-dependent and -independent mechanisms suggests that cannabinoids may modulate Müller cell functions through multiple pathways.

  6. Cannabinoid Receptor 2 Signaling in Neurodegenerative Disorders: From Pathogenesis to a Promising Therapeutic Target

    PubMed Central

    Cassano, Tommaso; Calcagnini, Silvio; Pace, Lorenzo; De Marco, Federico; Romano, Adele; Gaetani, Silvana

    2017-01-01

    As a consequence of an increasingly aging population, the number of people affected by neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease and Huntington's disease, is rapidly increasing. Although the etiology of these diseases has not been completely defined, common molecular mechanisms including neuroinflammation, excitotoxicity and mitochondrial dysfunction have been confirmed and can be targeted therapeutically. Moreover, recent studies have shown that endogenous cannabinoid signaling plays a number of modulatory roles throughout the central nervous system (CNS), including the neuroinflammation and neurogenesis. In particular, the up-regulation of type-2 cannabinoid (CB2) receptors has been found in a number of neurodegenerative disorders. Thus, the modulation of CB2 receptor signaling may represent a promising therapeutic target with minimal psychotropic effects that can be used to modulate endocannabinoid-based therapeutic approaches and to reduce neuronal degeneration. For these reasons this review will focus on the CB2 receptor as a promising pharmacological target in a number of neurodegenerative diseases. PMID:28210207

  7. Presynaptically located CB1 cannabinoid receptors regulate GABA release from axon terminals of specific hippocampal interneurons.

    PubMed

    Katona, I; Sperlágh, B; Sík, A; Käfalvi, A; Vizi, E S; Mackie, K; Freund, T F

    1999-06-01

    To understand the functional significance and mechanisms of action in the CNS of endogenous and exogenous cannabinoids, it is crucial to identify the neural elements that serve as the structural substrate of these actions. We used a recently developed antibody against the CB1 cannabinoid receptor to study this question in hippocampal networks. Interneurons with features typical of basket cells showed a selective, intense staining for CB1 in all hippocampal subfields and layers. Most of them (85.6%) contained cholecystokinin (CCK), which corresponded to 96.9% of all CCK-positive interneurons, whereas only 4.6% of the parvalbumin (PV)-containing basket cells expressed CB1. Accordingly, electron microscopy revealed that CB1-immunoreactive axon terminals of CCK-containing basket cells surrounded the somata and proximal dendrites of pyramidal neurons, whereas PV-positive basket cell terminals in similar locations were negative for CB1. The synthetic cannabinoid agonist WIN 55,212-2 (0.01-3 microM) reduced dose-dependently the electrical field stimulation-induced [3H]GABA release from superfused hippocampal slices, with an EC50 value of 0. 041 microM. Inhibition of GABA release by WIN 55,212-2 was not mediated by inhibition of glutamatergic transmission because the WIN 55,212-2 effect was not reduced by the glutamate blockers AP5 and CNQX. In contrast, the CB1 cannabinoid receptor antagonist SR 141716A (1 microM) prevented this effect, whereas by itself it did not change the outflow of [3H]GABA. These results suggest that cannabinoid-mediated modulation of hippocampal interneuron networks operate largely via presynaptic receptors on CCK-immunoreactive basket cell terminals. Reduction of GABA release from these terminals is the likely mechanism by which both endogenous and exogenous CB1 ligands interfere with hippocampal network oscillations and associated cognitive functions.

  8. Endogenous Cannabinoid Signaling Is Required for Voluntary Exercise-induced Enhancement of Progenitor Cell Proliferation in the Hippocampus

    PubMed Central

    Hill, Matthew N.; Titterness, Andrea K.; Morrish, Anna C.; Carrier, Erica J.; Lee, Tiffany T.-Y.; Gil-Mohapel, Joana; Gorzalka, Boris B.; Hillard, Cecilia J.; Christie, Brian R.

    2009-01-01

    Voluntary exercise and endogenous cannabinoid activity have independently been shown to regulate hippocampal plasticity. The aim of the current study was to determine whether the endocannabinoid system is regulated by voluntary exercise and if these changes contribute to exercise-induced enhancement of cell proliferation. In Experiment 1, eight days of free access to a running wheel increased the agonist binding site density of the cannabinoid CB1 receptor; CB1 receptor-mediated GTPγS binding; and the tissue content of the endocannabinoid anandamide in the hippocampus but not in the prefrontal cortex. In Experiment 2, the CB1 receptor antagonist AM251 (1 mg/kg) was administered daily to animals given free access to a running wheel for 8 days, after which cell proliferation in the hippocampus was examined through immunohistochemical analysis of the cell cycle protein Ki-67. Voluntary exercise increased proliferation of progenitor cells, as evidenced by the increase in the number of Ki-67 positive cells in the granule cell layer of the dentate gyrus in the hippocampus. However, this effect was abrogated by concurrent treatment with AM251, indicating that the increase in endocannabinoid signaling in the hippocampus is required for the exercise-induced increase in cell proliferation. These data demonstrate that the endocannabinoid system in the hippocampus is sensitive to environmental change and suggest that it is a mediator of experience-induced plasticity. PMID:19489006

  9. Cannabinoids Inhibit Insulin Receptor Signaling in Pancreatic β-Cells

    PubMed Central

    Kim, Wook; Doyle, Máire E.; Liu, Zhuo; Lao, Qizong; Shin, Yu-Kyong; Carlson, Olga D.; Kim, Hee Seung; Thomas, Sam; Napora, Joshua K.; Lee, Eun Kyung; Moaddel, Ruin; Wang, Yan; Maudsley, Stuart; Martin, Bronwen; Kulkarni, Rohit N.; Egan, Josephine M.

    2011-01-01

    OBJECTIVE Optimal glucose homeostasis requires exquisitely precise adaptation of the number of insulin-secreting β-cells in the islets of Langerhans. Insulin itself positively regulates β-cell proliferation in an autocrine manner through the insulin receptor (IR) signaling pathway. It is now coming to light that cannabinoid 1 receptor (CB1R) agonism/antagonism influences insulin action in insulin-sensitive tissues. However, the cells on which the CB1Rs are expressed and their function in islets have not been firmly established. We undertook the current study to investigate if intraislet endogenous cannabinoids (ECs) regulate β-cell proliferation and if they influence insulin action. RESEARCH DESIGN AND METHODS We measured EC production in isolated human and mouse islets and β-cell line in response to glucose and KCl. We evaluated human and mouse islets, several β-cell lines, and CB1R-null (CB1R−/−) mice for the presence of a fully functioning EC system. We investigated if ECs influence β-cell physiology through regulating insulin action and demonstrated the therapeutic potential of manipulation of the EC system in diabetic (db/db) mice. RESULTS ECs are generated within β-cells, which also express CB1Rs that are fully functioning when activated by ligands. Genetic and pharmacologic blockade of CB1R results in enhanced IR signaling through the insulin receptor substrate 2-AKT pathway in β-cells and leads to increased β-cell proliferation and mass. CB1R antagonism in db/db mice results in reduced blood glucose and increased β-cell proliferation and mass, coupled with enhanced IR signaling in β-cells. Furthermore, CB1R activation impedes insulin-stimulated IR autophosphorylation on β-cells in a Gαi-dependent manner. CONCLUSIONS These findings provide direct evidence for a functional interaction between CB1R and IR signaling involved in the regulation of β-cell proliferation and will serve as a basis for developing new therapeutic interventions to

  10. Receptors and Channels Targeted by Synthetic Cannabinoid Receptor Agonists and Antagonists

    PubMed Central

    Pertwee, R.G.

    2010-01-01

    It is widely accepted that non-endogenous compounds that target CB1 and/or CB2 receptors possess therapeutic potential for the clinical management of an ever growing number of disorders. Just a few of these disorders are already treated with Δ9-tetrahydrocannabinol or nabilone, both CB1/CB2 receptor agonists, and there is now considerable interest in expanding the clinical applications of such agonists and also in exploiting CB2-selective agonists, peripherally restricted CB1/CB2 receptor agonists and CB1/CB2 antagonists and inverse agonists as medicines. Already, numerous cannabinoid receptor ligands have been developed and their interactions with CB1 and CB2 receptors well characterized. This review describes what is currently known about the ability of such compounds to bind to, activate, inhibit or block non-CB1, non-CB2 G protein-coupled receptors such as GPR55, transmitter gated channels, ion channels and nuclear receptors in an orthosteric or allosteric manner. It begins with a brief description of how each of these ligands interacts with CB1 and/or CB2 receptors. PMID:20166927

  11. Inhibitory effect of salvinorin A, from Salvia divinorum, on ileitis-induced hypermotility: cross-talk between κ-opioid and cannabinoid CB1 receptors

    PubMed Central

    Capasso, R; Borrelli, F; Cascio, M G; Aviello, G; Huben, K; Zjawiony, J K; Marini, P; Romano, B; Di Marzo, V; Capasso, F; Izzo, A A

    2008-01-01

    Background and purpose: Salvinorin A, the active component of the hallucinogenic herb Salvia divinorum, inhibits intestinal motility through activation of κ-opioid receptors (KORs). However, this compound may have target(s) other than the KORs in the inflamed gut. Because intestinal inflammation upregulates cannabinoid receptors and endogenous cannabinoids, in the present study we investigated the possible involvement of the endogenous cannabinoid system in salvinorin A-induced delay in motility in the inflamed gut. Experimental approach: Motility in vivo was measured by evaluating the distribution of a fluorescent marker along the small intestine; intestinal inflammation was induced by the irritant croton oil; direct or indirect activity at cannabinoid receptors was evaluated by means of binding, enzymic and cellular uptake assays. Key results: Salvinorin A as well as the KOR agonist U-50488 reduced motility in croton oil treated mice. The inhibitory effect of both salvinorin A and U-50488 was counteracted by the KOR antagonist nor-binaltorphimine and by the cannabinoid CB1 receptor antagonist rimonabant. Rimonabant, however, did not counteract the inhibitory effect of salvinorin A on motility in control mice. Binding experiments showed very weak affinity of salvinorin A for cannabinoid CB1 and CB2 and no inhibitory effect on 2-arachidonoylglycerol and anandamide hydrolysis and cellular uptake. Conclusions and implications: The inhibitory effect of salvinorin A on motility reveals a functional interaction between cannabinoid CB1 receptors and KORs in the inflamed—but not in the normal—gut in vivo. PMID:18622408

  12. Basolateral amygdala CB1 cannabinoid receptors mediate nicotine-induced place preference.

    PubMed

    Hashemizadeh, Shiva; Sardari, Maryam; Rezayof, Ameneh

    2014-06-03

    In the present study, the effects of bilateral microinjections of cannabinoid CB1 receptor agonist and antagonist into the basolateral amygdala (intra-BLA) on nicotine-induced place preference were examined in rats. A conditioned place preference (CPP) apparatus was used for the assessment of rewarding effects of the drugs in adult male Wistar rats. Subcutaneous (s.c.) administration of nicotine (0.2mg/kg) induced a significant CPP, without any effect on the locomotor activity during the testing phase. Intra-BLA microinjection of a non-selective cannabinoid CB1/CB2 receptor agonist, WIN 55,212-2 (0.1-0.5 μg/rat) with an ineffective dose of nicotine (0.1mg/kg, s.c.) induced a significant place preference. On the other hand, intra-BLA administration of AM251 (20-60 ng/rat), a selective cannabinoid CB1 receptor antagonist inhibited the acquisition of nicotine-induced place preference. It should be considered that the microinjection of the same doses of WIN 55,212-2 or AM251 into the BLA, by itself had no effect on the CPP score. The administration of a higher dose of AM251 (60 ng/rat) during the acquisition decreased the locomotor activity of animals on the testing phase. Interestingly, the microinjection of AM251 (20 and 40 ng/rat), but not WIN55,212-2 (0.1-0.5 μg/rat), into the BLA inhibited the expression of nicotine-induced place preference without any effect on the locomotor activity. Taken together, these findings support the possible role of endogenous cannabinoid system of the BLA in the acquisition and the expression of nicotine-induced place preference. Furthermore, it seems that there is a functional interaction between the BLA cannabinoid receptors and nicotine in producing the rewarding effects.

  13. Cannabinoid 2 receptor- and beta Arrestin 2-dependent upregulation of serotonin 2A receptors.

    PubMed

    Franklin, J M; Vasiljevik, T; Prisinzano, T E; Carrasco, G A

    2013-07-01

    Recent evidence suggests that cannabinoid receptor agonists may regulate serotonin 2A (5-HT(2A)) receptor neurotransmission in the brain, although no molecular mechanism has been identified. Here, we present experimental evidence that sustained treatment with a non-selective cannabinoid agonist (CP55,940) or selective CB2 receptor agonists (JWH133 or GP1a) upregulate 5-HT(2A) receptors in a neuronal cell line. Furthermore, this cannabinoid receptor agonist-induced upregulation of 5-HT(2A) receptors was prevented in cells stably transfected with either CB2 or β-Arrestin 2 shRNA lentiviral particles. Additionally, inhibition of clathrin-mediated endocytosis also prevented the cannabinoid receptor-induced upregulation of 5-HT(2A) receptors. Our results indicate that cannabinoid agonists might upregulate 5-HT(2A) receptors by a mechanism that requires CB2 receptors and β-Arrestin 2 in cells that express both CB2 and 5-HT(2A) receptors. 5-HT(2A) receptors have been associated with several physiological functions and neuropsychiatric disorders such as stress response, anxiety and depression, and schizophrenia. Therefore, these results might provide a molecular mechanism by which activation of cannabinoid receptors might be relevant to some cognitive and mood disorders in humans.

  14. Activation of phosphoinositide 3-kinase/PKB pathway by CB(1) and CB(2) cannabinoid receptors expressed in prostate PC-3 cells. Involvement in Raf-1 stimulation and NGF induction.

    PubMed

    Sánchez, María G; Ruiz-Llorente, Lidia; Sánchez, Ana M; Díaz-Laviada, Inés

    2003-09-01

    Cannabinoids exert a variety of physiological and pharmacological responses in humans through interaction with specific cannabinoid receptors. Cannabinoid receptors described to date belong to the seven-transmembrane-domain receptor superfamily and are coupled through the inhibitory G(i) protein to adenylyl cyclase inhibition. However, downstream signal transduction mechanisms triggered by cannabinoids are poorly understood. We examined here the involvement of the phosphoinositide 3-kinase (PI3K)/PKB pathway in the mechanism of action of cannabinoids in human prostate epithelial PC-3 cells. Cannabinoid receptors CB(1) and CB(2) are expressed in these cells, as shown by RT-PCR, Western blot and immunofluorescence techniques. Treatment of PC-3 cells with either Delta(9)-tetrahydrocannabinol (THC), the major psychoactive ingredient of marijuana, or R-(+)-methanandamide (MET), an analogue of the endogenous cannabinoid anandamide, increased phosphorylation of PKB in Thr308 and Ser473. The stimulation of PKB induced by cannabinoids was blocked by the two cannabinoid receptor antagonists, SR 141716 and SR 144528, and by the PI3K inhibitor LY 294002. These results indicate that activation of cannabinoid receptors in PC-3 cells stimulate the PI3K/PKB pathway. We further investigated the involvement of Raf-1/Erk activation in the mechanism of action of cannabinoid receptors. THC and MET induced translocation of Raf-1 to the membrane and phosphorylation of p44/42 Erk kinase, which was reversed by cannabinoid receptor antagonists and PI3K inhibitor. These results point to a sequential connection between cannabinoid receptors/PI3K/PKB pathway and Raf-1/Erk in prostate PC-3 cells. We also show that this pathway is involved in the mechanism of NGF induction exerted by cannabinoids in PC-3 cells.

  15. Cannabinoid Receptors: A Novel Target for Therapy for Prostate Cancer

    DTIC Science & Technology

    2008-02-01

    cannabinoids could used in the management of prostate cancer. Table of Contents Background.…………………………………………………………….…………4-5 Body ...whether cannabinoid receptors could prove to be useful targets for the treatment of prostate cancer. Body Specific Aims: The following specific...stream of the host. WIN-55,212-2 treatment did not cause any loss in the body weight, food intake, or exhibited apparent signs of toxicity in animals

  16. Modulation of the cannabinoid receptors by hemopressin peptides

    PubMed Central

    Bomar, Martha G.

    2012-01-01

    Changes in the endocannabinoid system are implicated in numerous diseases, making it an attractive target for pharmaceutical development. The endocannabinoid receptors have traditionally been thought to act through the effects of lipophilic messengers called cannabinoids. The exciting finding of endocannabinoid system modulation by the nonapeptide hemopressin and its N-terminal extensions has highlighted the complexity of cannabinoid biology and pharmacology and sparked interest for therapeutic purposes. However, many questions surrounding the generation and regulation of the hemopressin peptides, the self-assembly of hemopressin and the potential for drug development based on hemopressin remain and are discussed in this review. PMID:22884803

  17. The cannabinoid receptor 1 associates with NMDA receptors to produce glutamatergic hypofunction: implications in psychosis and schizophrenia

    PubMed Central

    Sánchez-Blázquez, Pilar; Rodríguez-Muñoz, María; Garzón, Javier

    2014-01-01

    The endocannabinoid system is widespread throughout the central nervous system and its type 1 receptor (CB1) plays a crucial role in preventing the neurotoxicity caused by activation of glutamate N-methyl-D-aspartate receptors (NMDARs). Indeed, it is the activity of NMDARs themselves that provides the demands on the endogenous cannabinoids in order to control their calcium currents. Therefore, a physiological role of this system is to maintain NMDAR activity within safe limits, thereby protecting neural cells from excitotoxicity. Thus, cannabinoids may be able to control NMDAR overactivation-related neural dysfunctions; however, the major obstacles to the therapeutic utilization of these compounds are their psychotropic effects and negative influence on cognitive performance. Studies in humans have indicated that abuse of smoked cannabis can promote psychosis and even circumstantially precipitate symptoms of schizophrenia, although the latter appears to require a prior vulnerability in the individual. It is possible that cannabinoids provoke psychosis/schizophrenia reflecting a mechanism common to neuroprotection: the reduction of NMDAR activity. Cannabinoids are proposed to produce such effect by reducing the pre-synaptic release of glutamate or interfering with post-synaptic NMDAR-regulated signaling pathways. The efficacy of such control requires the endocannabinoid system to apply its negative influence in a manner that is proportional to the strength of NMDAR signaling. Thus, cannabinoids acting at the wrong time or exerting an inappropriate influence on their receptors may cause NMDAR hypofunction. The purpose of the present review is to draw the attention of the reader to the newly described functional and physical CB1–NMDAR association, which may elucidate the scenario required for the rapid and efficacious control of NMDAR activity. Whether alterations in these mechanisms may increase NMDAR hypofunction leading to vulnerability to schizophrenia will be

  18. Endocannabinoid release from midbrain dopamine neurons: a potential substrate for cannabinoid receptor antagonist treatment of addiction.

    PubMed

    Lupica, Carl R; Riegel, Arthur C

    2005-06-01

    Substantial evidence suggests that all commonly abused drugs act upon the brain reward circuitry to ultimately increase extracellular concentrations of the neurotransmitter dopamine in the nucleus accumbens and other forebrain areas. Many drugs of abuse appear to increase dopamine levels by dramatically increase the firing and bursting rates of dopamine neurons located in the ventral mesencephalon. Recent clinical evidence in humans and behavioral evidence in animals indicate that cannabinoid receptor antagonists such as SR141716A (Rimonabant) can reduce the self-administration of, and craving for, several commonly addictive drugs. However, the mechanism of this potentially beneficial effect has not yet been identified. We propose, on the basis of recent studies in our laboratory and others, that these antagonists may act by blocking the effects of endogenously released cannabinoid molecules (endocannabinoids) that are released in an activity- and calcium-dependent manner from mesencephalic dopamine neurons. It is hypothesized that, through the antagonism of cannabinoid CB1 receptors located on inhibitory and excitatory axon terminals targeting the midbrain dopamine neurons, the effects of the endocannabinoids are occluded. The data from these studies therefore suggest that the endocannabinoid system and the CB1 receptors located in the ventral mesencephalon may play an important role in regulating drug reward processes, and that this substrate is recruited whenever dopamine neuron activity is increased.

  19. Cannabinoid receptor-independent cytotoxic effects of cannabinoids in human colorectal carcinoma cells: synergism with 5-fluorouracil.

    PubMed

    Gustafsson, Sofia B; Lindgren, Theres; Jonsson, Maria; Jacobsson, Stig O P

    2009-03-01

    Cannabinoids (CBs) have been found to exert antiproliferative effects upon a variety of cancer cells, including colorectal carcinoma cells. However, little is known about the signalling mechanisms behind the antitumoural effect in these cells, whether the effects are shared by endogenous lipids related to endocannabinoids, or whether such effects are synergistic with treatment paradigms currently used in the clinic. The aim of this preclinical study was to investigate the effect of synthetic and endogenous CBs and their related fatty acids on the viability of human colorectal carcinoma Caco-2 cells, and to determine whether CB effects are synergistic with those seen with the pyrimidine antagonist 5-fluorouracil (5-FU). The synthetic CB HU 210, the endogenous CB anandamide, the endogenous structural analogue of anandamide, N-arachidonoyl glycine (NAGly), as well as the related polyunsaturated fatty acids arachidonic acid and eicosapentaenoic acid showed antiproliferative and cytotoxic effects in the Caco-2 cells, as measured by using [(3)H]-thymidine incorporation assay, the CyQUANT proliferation assay and calcein-AM fluorescence. HU 210 was the most potent compound examined, followed by anandamide, whereas NAGly showed equal potency and efficacy as the polyunsaturated fatty acids. Furthermore, HU 210 and 5-FU produced synergistic effects in the Caco-2 cells, but not in the human colorectal carcinoma cell lines HCT116 or HT29. The compounds examined produced cytotoxic, rather than antiproliferative effects, by a mechanism not involving CB receptors, since the CB receptor antagonists AM251 and AM630 did not attenuate the effects, nor did pertussis toxin. However, alpha-tocopherol and the nitric oxide synthase inhibitor L-NAME attenuated the CB toxicity, suggesting involvement of oxidative stress. It is concluded that the CB system may provide new targets for the development of drugs to treat colorectal cancer.

  20. Type 1 cannabinoid receptor ligands display functional selectivity in a cell culture model of striatal medium spiny projection neurons.

    PubMed

    Laprairie, Robert B; Bagher, Amina M; Kelly, Melanie E M; Dupré, Denis J; Denovan-Wright, Eileen M

    2014-09-05

    Modulation of type 1 cannabinoid receptor (CB1) activity has been touted as a potential means of treating addiction, anxiety, depression, and neurodegeneration. Different agonists of CB1 are known to evoke varied responses in vivo. Functional selectivity is the ligand-specific activation of certain signal transduction pathways at a receptor that can signal through multiple pathways. To understand cannabinoid-specific functional selectivity, different groups have examined the effect of individual cannabinoids on various signaling pathways in heterologous expression systems. In the current study, we compared the functional selectivity of six cannabinoids, including two endocannabinoids (2-arachidonyl glycerol (2-AG) and anandamide (AEA)), two synthetic cannabinoids (WIN55,212-2 and CP55,940), and two phytocannabinoids (cannabidiol (CBD) and Δ(9)-tetrahydrocannabinol (THC)) on arrestin2-, Gα(i/o)-, Gβγ-, Gα(s)-, and Gα(q)-mediated intracellular signaling in the mouse STHdh(Q7/Q7) cell culture model of striatal medium spiny projection neurons that endogenously express CB1. In this system, 2-AG, THC, and CP55,940 were more potent mediators of arrestin2 recruitment than other cannabinoids tested. 2-AG, AEA, and WIN55,212-2, enhanced Gα(i/o) and Gβγ signaling, with 2-AG and AEA treatment leading to increased total CB1 levels. 2-AG, AEA, THC, and WIN55,212-2 also activated Gα(q)-dependent pathways. CP55,940 and CBD both signaled through Gα(s). CP55,940, but not CBD, activated downstream Gα(s) pathways via CB1 targets. THC and CP55,940 promoted CB1 internalization and decreased CB1 protein levels over an 18-h period. These data demonstrate that individual cannabinoids display functional selectivity at CB1 leading to activation of distinct signaling pathways. To effectively match cannabinoids with therapeutic goals, these compounds must be screened for their signaling bias.

  1. Cannabinoid type 1 receptor: another arrow in the adipocytes' bow.

    PubMed

    Bellocchio, L; Cervino, C; Vicennati, V; Pasquali, R; Pagotto, U

    2008-05-01

    The endocannabinoid system has recently emerged as an important modulator of several functions of adipose tissue, including cell proliferation, differentiation and secretion. Here, we will review the effects of cannabinoid type 1 (CB(1)) receptor activation/blockade in adipocytes by summarising the data in the literature since the discovery of the presence of this receptor in adipose tissue. We will also discuss our original data obtained in mouse 3T3-L1 adipocyte cells using WIN55 212, a CB(1)/CB(2) receptor agonist and SR141716 (rimonabant), a specific CB(1) receptor antagonist, respectively, in different experimental settings.

  2. C3-heteroaroyl cannabinoids as photolabeling ligands for the CB2 cannabinoid receptor.

    PubMed

    Dixon, Darryl D; Tius, Marcus A; Thakur, Ganesh A; Zhou, Han; Bowman, Anna L; Shukla, Vidyanand G; Peng, Yan; Makriyannis, Alexandros

    2012-08-15

    A series of tricyclic cannabinoids incorporating a heteroaroyl group at C3 were prepared as probes to explore the binding site(s) of the CB1 and CB2 receptors. This relatively unexplored structural motif is shown to be CB2 selective with K(i) values at low nanomolar concentrations when the heteroaromatic group is 3-benzothiophenyl (41) or 3-indolyl (50). When photoactivated, the lead compound 41 was shown to successfully label the CB2 receptor through covalent attachment at the active site while 50 failed to label. The benzothiophenone moiety may be a photoactivatable moiety suitable for selective labeling.

  3. Inhibiting the breakdown of endogenous opioids and cannabinoids to alleviate pain.

    PubMed

    Roques, Bernard P; Fournié-Zaluski, Marie-Claude; Wurm, Michel

    2012-04-01

    Chronic pain remains unsatisfactorily treated, and few novel painkillers have reached the market in the past century. Increasing the levels of the main endogenous opioid peptides - enkephalins - by inhibiting their two inactivating ectopeptidases, neprilysin and aminopeptidase N, has analgesic effects in various models of inflammatory and neuropathic pain. Stemming from the same pharmacological concept, fatty acid amide hydrolase (FAAH) inhibitors have also been found to have analgesic effects in pain models by preventing the breakdown of endogenous cannabinoids. Dual enkephalinase inhibitors and FAAH inhibitors are now in early-stage clinical trials. In this Review, we compare the effects of these two potential classes of novel analgesics and describe the progress in their rational design. We also consider the challenges in their clinical development and opportunities for combination therapies.

  4. Cannabinoids inhibit insulin secretion and cytosolic Ca2+ oscillation in islet beta-cells via CB1 receptors.

    PubMed

    Nakata, Masanori; Yada, Toshihiko

    2008-01-10

    Obesity is the main risk factor for the development of metabolic syndrome. Endogenous cannabinoids act on the cannabinoid type 1 (CB1) receptor, a GPCR, and stimulate appetite via central and peripheral actions, while blockade of CB1 receptor reduces body weight in humans. In this study, we aimed to explore a role of the peripheral endocannabinoid system in insulin secretion, which could be important in the metabolic effects of the cannabinoid-CB1 system. We found that mRNA for CB1 receptor, but not CB2 receptor, was expressed in mouse pancreatic islets using RT-PCR. Immunohistochemical study revealed that CB1 receptor was expressed in beta-cells. Furthermore, anandamide and a CB1 agonist, arachidonylcyclopropylamide (ACPA), inhibited glucose-induced insulin secretion from mouse pancreatic islets. Both anandamide and ACPA inhibited glucose-induced cytosolic Ca(2+) oscillation in mouse pancreatic beta-cells. These results demonstrate a novel peripheral action of cannabinoids to inhibit insulin secretion via CB1 receptors.

  5. Endogenous cannabinoid release within prefrontal-limbic pathways affects memory consolidation of emotional training.

    PubMed

    Morena, Maria; Roozendaal, Benno; Trezza, Viviana; Ratano, Patrizia; Peloso, Andrea; Hauer, Daniela; Atsak, Piray; Trabace, Luigia; Cuomo, Vincenzo; McGaugh, James L; Schelling, Gustav; Campolongo, Patrizia

    2014-12-23

    Previous studies have provided extensive evidence that administration of cannabinoid drugs after training modulates the consolidation of memory for an aversive experience. The present experiments investigated whether the memory consolidation is regulated by endogenously released cannabinoids. The experiments first examined whether the endocannabinoids anandamide (AEA) and 2-arachidonoyl glycerol (2-AG) are released by aversive training. Inhibitory avoidance training with higher footshock intensity produced increased levels of AEA in the amygdala, hippocampus, and medial prefrontal cortex (mPFC) shortly after training in comparison with levels assessed in rats trained with lower footshock intensity or unshocked controls exposed only to the training apparatus. In contrast, 2-AG levels were not significantly elevated. The additional finding that posttraining infusions of the fatty acid amide hydrolase (FAAH) inhibitor URB597, which selectively increases AEA levels at active synapses, administered into the basolateral complex of the amygdala (BLA), hippocampus, or mPFC enhanced memory strongly suggests that the endogenously released AEA modulates memory consolidation. Moreover, in support of the view that this emotional training-associated increase in endocannabinoid neurotransmission, and its effects on memory enhancement, depends on the integrity of functional interactions between these different brain regions, we found that disruption of BLA activity blocked the training-induced increases in AEA levels as well as the memory enhancement produced by URB597 administered into the hippocampus or mPFC. Thus, the findings provide evidence that emotionally arousing training increases AEA levels within prefrontal-limbic circuits and strongly suggest that this cannabinoid activation regulates emotional arousal effects on memory consolidation.

  6. Failure to extinguish fear and genetic variability in the human cannabinoid receptor 1.

    PubMed

    Heitland, I; Klumpers, F; Oosting, R S; Evers, D J J; Leon Kenemans, J; Baas, J M P

    2012-09-25

    Failure to extinguish fear can lead to persevering anxiety and has been postulated as an important mechanism in the pathogenesis of human anxiety disorders. In animals, it is well documented that the endogenous cannabinoid system has a pivotal role in the successful extinction of fear, most importantly through the cannabinoid receptor 1. However, no human studies have reported a translation of this preclinical evidence yet. Healthy medication-free human subjects (N=150) underwent a fear conditioning and extinction procedure in a virtual reality environment. Fear potentiation of the eyeblink startle reflex was measured to assess fear-conditioned responding, and subjective fear ratings were collected. Participants were genotyped for two polymorphisms located within the promoter region (rs2180619) and the coding region (rs1049353) of cannabinoid receptor 1. As predicted from the preclinical literature, acquisition and expression of conditioned fear did not differ between genotypes. Crucially, whereas both homozygote (G/G, N=23) and heterozygote (A/G, N=68) G-allele carriers of rs2180619 displayed robust extinction of fear, extinction of fear-potentiated startle was absent in A/A homozygotes (N=51). Additionally, this resistance to extinguish fear left A/A carriers of rs2180619 with significantly higher levels of fear-potentiated startle at the end of the extinction training. No effects of rs1049353 genotype were observed regarding fear acquisition and extinction. These results suggest for the first time involvement of the human endocannabinoid system in fear extinction. Implications are that genetic variability in this system may underlie individual differences in anxiety, rendering cannabinoid receptor 1 a potential target for novel pharmacological treatments of anxiety disorders.

  7. Monoglyceride lipase deficiency causes desensitization of intestinal cannabinoid receptor type 1 and increased colonic μ-opioid receptor sensitivity

    PubMed Central

    Taschler, U; Eichmann, T O; Radner, F P W; Grabner, G F; Wolinski, H; Storr, M; Lass, A; Schicho, R; Zimmermann, R

    2015-01-01

    Background and Purpose Monoglyceride lipase (MGL) degrades 2-arachidonoyl glycerol (2-AG), an endogenous agonist of cannabinoid receptors (CB1/2). Because the CB1 receptor is involved in the control of gut function, we investigated the effects of pharmacological inhibition and genetic deletion of MGL on intestinal motility. Furthermore, we determined whether defective 2-AG degradation affects μ-opioid receptorreceptor) signalling, a parallel pathway regulating gut motility. Experimental Approach Gut motility was investigated by monitoring Evans Blue transit and colonic bead propulsion in response to MGL inhibition and CB1 receptor or μ receptor stimulation. Ileal contractility was investigated by electrical field stimulation. CB1 receptor expression in ileum and colon was assessed by immunohistochemical analyses. Key Results Pharmacological inhibition of MGL slowed down whole gut transit in a CB1 receptor-dependent manner. Conversely, genetic deletion of MGL did not affect gut transit despite increased 2-AG levels. Notably, MGL deficiency caused complete insensitivity to CB1 receptor agonist-mediated inhibition of whole gut transit and ileal contractility suggesting local desensitization of CB1 receptors. Accordingly, immunohistochemical analyses of myenteric ganglia of MGL-deficient mice revealed that CB1 receptors were trapped in endocytic vesicles. Finally, MGL-deficient mice displayed accelerated colonic propulsion and were hypersensitive to μ receptor agonist-mediated inhibition of colonic motility. This phenotype was reproduced by chronic pharmacological inhibition of MGL. Conclusion and Implications Constantly elevated 2-AG levels induce severe desensitization of intestinal CB1 receptors and increased sensitivity to μ receptor-mediated inhibition of colonic motility. These changes should be considered when cannabinoid-based drugs are used in the therapy of gastrointestinal diseases. PMID:26075589

  8. CB2 Cannabinoid Receptors as a Therapeutic Target—What Does the Future Hold?

    PubMed Central

    Dhopeshwarkar, Amey

    2014-01-01

    The past decades have seen an exponential rise in our understanding of the endocannabinoid system, comprising CB1 and CB2 cannabinoid receptors, endogenous cannabinoids (endocannabinoids), and the enzymes that synthesize and degrade endocannabinoids. The primary focus of this review is the CB2 receptor. CB2 receptors have been the subject of considerable attention, primarily due to their promising therapeutic potential for treating various pathologies while avoiding the adverse psychotropic effects that can accompany CB1 receptor–based therapies. With the appreciation that CB2-selective ligands show marked functional selectivity, there is a renewed opportunity to explore this promising area of research from both a mechanistic as well as a therapeutic perspective. In this review, we summarize our present knowledge of CB2 receptor signaling, localization, and regulation. We discuss the availability of genetic tools (and their limitations) to study CB2 receptors and also provide an update on preclinical data on CB2 agonists in pain models. Finally, we suggest possible reasons for the failure of CB2 ligands in clinical pain trials and offer possible ways to move the field forward in a way that can help reconcile the inconsistencies between preclinical and clinical data. PMID:25106425

  9. Persistently active cannabinoid receptors mute a subpopulation of hippocampal interneurons.

    PubMed

    Losonczy, Attila; Biró, Agota A; Nusser, Zoltan

    2004-02-03

    Cortical information processing requires an orchestrated interaction between a large number of pyramidal cells and albeit fewer, but highly diverse GABAergic interneurons (INs). The diversity of INs is thought to reflect functional and structural specializations evolved to control distinct network operations. Consequently, specific cortical functions may be selectively modified by altering the input-output relationship of unique IN populations. Here, we report that persistently active cannabinoid receptors, the site of action of endocannabinoids, and the psychostimulants marijuana and hashish, switch off the output (mute) of a unique class of hippocampal INs. In paired recordings between cholecystokinin-immunopositive, mossy fiber-associated INs, and their target CA3 pyramidal cells, no postsynaptic currents could be evoked with single presynaptic action potentials or with repetitive stimulations at frequencies <25 Hz. Cannabinoid receptor antagonists converted these "mute" synapses into high-fidelity ones. The selective muting of specific GABAergic INs, achieved by persistent presynaptic cannabinoid receptor activation, provides a state-dependent switch in cortical networks.

  10. Evaluation of the neuroprotective effect of cannabinoids in a rat model of Parkinson's disease: importance of antioxidant and cannabinoid receptor-independent properties.

    PubMed

    García-Arencibia, Moisés; González, Sara; de Lago, Eva; Ramos, José A; Mechoulam, Raphael; Fernández-Ruiz, Javier

    2007-02-23

    , a key enzyme in endogenous defenses against oxidative stress. In summary, our results indicate that those cannabinoids having antioxidant cannabinoid receptor-independent properties provide neuroprotection against the progressive degeneration of nigrostriatal dopaminergic neurons occurring in PD. In addition, the activation of CB2 (but not CB1) receptors, or other additional mechanisms, might also contribute to some extent to the potential of cannabinoids in this disease.

  11. Cannabinoid-receptor-independent cell signalling by N-acylethanolamines.

    PubMed Central

    Berdyshev, E V; Schmid, P C; Krebsbach, R J; Hillard, C J; Huang, C; Chen, N; Dong, Z; Schmid, H H

    2001-01-01

    Anandamide and other polyunsaturated N-acylethanolamines (NAEs) exert biological activity by binding to cannabinoid receptors. These receptors are linked to G(i/o) proteins and their activation leads to extracellular-signal-regulated protein kinase (ERK) and c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAP kinase) activation, inhibition of cAMP-dependent signalling and complex changes in the expression of various genes. Saturated and monounsaturated NAEs cannot bind to cannabinoid receptors and may thus mediate cell signalling through other targets. Here we report that both saturated/monounsaturated NAEs and anandamide (20:4(n-6) NAE) stimulate cannabinoid-receptor-independent ERK phosphorylation and activator protein-1 (AP-1)-dependent transcriptional activity in mouse epidermal JB6 cells. Using a clone of JB6 P(+) cells with an AP-1 collagen-luciferase reporter construct, we found that 16:0, 18:1(n-9), 18:1(n-7), 18:2(n-6) and 20:4(n-6) NAEs stimulated AP-1-dependent transcriptional activity up to 2-fold, with maximal stimulation at approx. 10-15 microM. Higher NAE concentrations had toxic effects mediated by alterations in mitochondrial energy metabolism. The AP-1 stimulation appeared to be mediated by ERK but not JNK or p38 signalling pathways, because all NAEs stimulated ERK1/ERK2 phosphorylation without having any effect on JNK or p38 kinases. Also, overexpression of dominant negative ERK1/ERK2 kinases completely abolished NAE-induced AP-1 activation. In contrast with 18:1(n-9) NAE and anandamide, the cannabinoid receptor agonist WIN 55,212-2 did not stimulate AP-1 activity and inhibited ERK phosphorylation. The NAE-mediated effects were not attenuated by pertussis toxin and appeared to be NAE-specific, as a close structural analogue, oleyl alcohol, failed to induce ERK phosphorylation. The data support our hypothesis that the major saturated and monounsaturated NAEs are signalling molecules acting through intracellular targets without

  12. Lack of CB1 cannabinoid receptors modifies nicotine behavioural responses, but not nicotine abstinence.

    PubMed

    Castañé, A; Valjent, E; Ledent, C; Parmentier, M; Maldonado, R; Valverde, O

    2002-10-01

    Cannabis is the most widely consumed illicit drug and its consumption is currently associated with tobacco, which contains another psychoactive compound, namely nicotine. Interactions between cannabinoids and other drugs of abuse, such as opioids, have been previously reported. The aim of the present study was to evaluate the possible role of CB1 cannabinoid receptor in responses induced by acute and repeated nicotine administration by using knockout mice lacking the CB1 cannabinoid receptor and their wild-type littermates. Acute nicotine (0.5, 1, 3 and 6 mg/kg, sc) administration decreased locomotor activity and induced antinociceptive responses in the tail-immersion and the hot-plate test, in wild-type animals. The antinociceptive effects in the tail-immersion test were significantly enhanced in CB1 knockout mice. In wild-type mice nicotine (0.5 mg/kg, sc) produced a significant rewarding effect, as measured by a conditioned place preference paradigm. This response was absent in CB1 knockout mice. Finally, a model of mecamylamine-induced abstinence in chronic nicotine-treated mice (10 mg/kg/day, sc) was developed. Mecamylamine (1 and 2 mg/kg, sc) precipitated several somatic signs of nicotine withdrawal in wild-type dependent mice. However, no difference in the severity of nicotine withdrawal was observed in CB1 knockout mice. These results demonstrate that some acute effects and motivational responses elicited by nicotine can be modulated by the endogenous cannabinoid system and support the existence of a physiological interaction between these two systems.

  13. 3′-Functionalized Adamantyl Cannabinoid Receptor Probes

    PubMed Central

    Ogawa, Go; Tius, Marcus A.; Zhou, Han; Nikas, Spyros P.; Halikhedkar, Aneetha; Mallipeddi, Srikrishnan; Makriyannis, Alexandros

    2015-01-01

    The aliphatic side chain plays a pivotal role in determining the cannabinergic potency of tricyclic classical cannabinoids, and we have previously shown that this chain could be substituted successfully by adamantyl or other polycyclic groups. In an effort to explore the pharmacophoric features of these conformationally fixed groups, we have synthesized a series of analogues in which the C3 position is substituted directly with an adamantyl group bearing functionality at one of the tertiary carbon atoms. These substituents included the electrophilic isothiocyanate and photoactivatable azido groups, both of which are capable of covalent attachment with the target protein. Our results show that substitution at the 3′-adamantyl position can lead to ligands with improved affinities and CB1/CB2 selectivities. Our work has also led to the development of two successful covalent probes with high affinities for both cannabinoid receptors, namely, the electrophilic isothiocyanate AM994 and the photoactivatable aliphatic azido AM993 analogues. PMID:25760146

  14. Cannabinoid receptor 2: potential role in immunomodulation and neuroinflammation.

    PubMed

    Rom, Slava; Persidsky, Yuri

    2013-06-01

    An accumulating body of evidence suggests that endocannabinoids and cannabinoid receptors type 1 and 2 (CB(1), CB(2)) play a significant role in physiologic and pathologic processes, including cognitive and immune functions. While the addictive properties of marijuana, an extract from the Cannabis plant, are well recognized, there is growing appreciation of the therapeutic potential of cannabinoids in multiple pathologic conditions involving chronic inflammation (inflammatory bowel disease, arthritis, autoimmune disorders, multiple sclerosis, HIV-1 infection, stroke, Alzheimer's disease to name a few), mainly mediated by CB(2) activation. Development of CB(2) agonists as therapeutic agents has been hampered by the complexity of their intracellular signaling, relative paucity of highly selective compounds and insufficient data regarding end effects in the target cells and organs. This review attempts to summarize recent advances in studies of CB(2) activation in the setting of neuroinflammation, immunomodulation and HIV-1 infection.

  15. Cannabinoids increase type 1 cannabinoid receptor expression in a cell culture model of striatal neurons: implications for Huntington's disease.

    PubMed

    Laprairie, Robert B; Kelly, Melanie E M; Denovan-Wright, Eileen M

    2013-09-01

    The type 1 cannabinoid receptor (CB1) is a G protein-coupled receptor that is expressed at high levels in the striatum. Activation of CB1 increases expression of neuronal trophic factors and inhibits neurotransmitter release from GABA-ergic striatal neurons. CB1 mRNA levels can be elevated by treatment with cannabinoids in non-neuronal cells. We wanted to determine whether cannabinoid treatment could induce CB1 expression in a cell culture model of striatal neurons and, if possible, determine the molecular mechanism by which this occurred. We found that treatment of STHdh(7/7) cells with the cannabinoids ACEA, mAEA, and AEA produced a CB1receptor-dependent increase in CB1 promoter activity, mRNA, and protein expression. This response was Akt- and NF-κB-dependent. Because decreased CB1 expression is thought to contribute to the pathogenesis of Huntington's disease (HD), we wanted to determine whether cannabinoids could increase CB1 expression in STHdh(7/111) and (111/111) cells expressing the mutant huntingtin protein. We observed that cannabinoid treatment increased CB1 mRNA levels approximately 10-fold in STHdh(7/111) and (111/111) cells, compared to vehicle treatment. Importantly, cannabinoid treatment improved ATP production, increased the expression of the trophic factor BDNF-2, and the mitochondrial regulator PGC1α, and reduced spontaneous GABA release, in HD cells. Therefore, cannabinoid-mediated increases in CB1 levels could reduce the severity of some molecular pathologies observed in HD.

  16. Cannabinoid-induced mesenteric vasodilation through an endothelial site distinct from CB1 or CB2 receptors

    PubMed Central

    Járai, Zoltán; Wagner, Jens A.; Varga, Károly; Lake, Kristy D.; Compton, David R.; Martin, Billy R.; Zimmer, Anne M.; Bonner, Tom I.; Buckley, Nancy E.; Mezey, Eva; Razdan, Raj K.; Zimmer, Andreas; Kunos, George

    1999-01-01

    Cannabinoids, including the endogenous ligand arachidonyl ethanolamide (anandamide), elicit not only neurobehavioral but also cardiovascular effects. Two cannabinoid receptors, CB1 and CB2, have been cloned, and studies with the selective CB1 receptor antagonist SR141716A have implicated peripherally located CB1 receptors in the hypotensive action of cannabinoids. In rat mesenteric arteries, anandamide-induced vasodilation is inhibited by SR141716A, but other potent CB1 receptor agonists, such as HU-210, do not cause vasodilation, which implicates an as-yet-unidentified receptor in this effect. Here we show that “abnormal cannabidiol” (Abn-cbd) is a neurobehaviorally inactive cannabinoid that does not bind to CB1 receptors, yet causes SR141716A-sensitive hypotension and mesenteric vasodilation in wild-type mice and in mice lacking CB1 receptors or both CB1 and CB2 receptors. Hypotension by Abn-cbd is also inhibited by cannabidiol (20 μg/g), which does not influence anandamide- or HU-210-induced hypotension. In the rat mesenteric arterial bed, Abn-cbd-induced vasodilation is unaffected by blockade of endothelial NO synthase, cyclooxygenase, or capsaicin receptors, but it is abolished by endothelial denudation. Mesenteric vasodilation by Abn-cbd, but not by acetylcholine, sodium nitroprusside, or capsaicine, is blocked by SR141716A (1 μM) or by cannabidiol (10 μM). Abn-cbd-induced vasodilation is also blocked in the presence of charybdotoxin (100 nM) plus apamin (100 nM), a combination of K+-channel toxins reported to block the release of an endothelium-derived hyperpolarizing factor (EDHF). These findings suggest that Abn-cbd and cannabidiol are a selective agonist and antagonist, respectively, of an as-yet-unidentified endothelial receptor for anandamide, activation of which elicits NO-independent mesenteric vasodilation, possibly by means of the release of EDHF. PMID:10570211

  17. Cannabinoid receptor stimulation increases motivation for nicotine and nicotine seeking.

    PubMed

    Gamaleddin, Islam; Wertheim, Carrie; Zhu, Andy Z X; Coen, Kathleen M; Vemuri, Kiran; Makryannis, Alex; Goldberg, Steven R; Le Foll, Bernard

    2012-01-01

    The cannabinoid system appears to play a critical facilitative role in mediating the reinforcing effects of nicotine and relapse to nicotine-seeking behaviour in abstinent subjects based on the actions of cannabinoid (CB) receptor antagonists. However, the effects of CB receptor stimulation on nicotine self-administration and reinstatement have not been systematically studied. Here, we studied the effects of WIN 55,212-2, a CB1/2 agonist, on intravenous nicotine self-administration under fixed-ratio (FR) and progressive-ratio (PR) schedules of reinforcement in rats. The effects of WIN 55,212-2 on responding for food under similar schedules were also studied. In addition, the effects of WIN 55,212-2 on nicotine- and cue-induced reinstatement of nicotine seeking were also studied, as well as the effects of WIN 55,212-2 on nicotine discrimination. WIN 55,212-2 decreased nicotine self-administration under the FR schedule. However, co-administration of WIN 55,212-2 with nicotine decreased responding for food, which suggests that this effect was non-selective. In contrast, WIN 55,212-2 increased both nicotine self-administration and responding for food under the PR schedule, produced dose-dependent reinstatement of nicotine seeking, and enhanced the reinstatement effects of nicotine-associated cues. Some of these effects were reversed by the CB1 antagonist rimonabant, but not by the CB2 antagonist AM630. In the drug discrimination tests between saline and 0.4 mg/kg nicotine, WIN 55,212-2 produced no nicotine-like discriminative effects but significantly potentiated discriminative stimulus effects of nicotine at the low dose through a CB1-receptor-dependent mechanism. These findings indicate that cannabinoid CB1-receptor stimulation increases the reinforcing effects of nicotine and precipitates relapse to nicotine-seeking behaviour in abstinent subjects. Thus, modulating CB1-receptor signalling might have therapeutic value for treating nicotine dependence.

  18. Cytotoxicity of synthetic cannabinoids on primary neuronal cells of the forebrain: the involvement of cannabinoid CB{sub 1} receptors and apoptotic cell death

    SciTech Connect

    Tomiyama, Ken-ichi; Funada, Masahiko

    2014-01-01

    The abuse of herbal products containing synthetic cannabinoids has become an issue of public concern. The purpose of this paper was to evaluate the acute cytotoxicity of synthetic cannabinoids on mouse brain neuronal cells. Cytotoxicity induced by synthetic cannabinoid (CP-55,940, CP-47,497, CP-47,497-C8, HU-210, JWH-018, JWH-210, AM-2201, and MAM-2201) was examined using forebrain neuronal cultures. These synthetic cannabinoids induced cytotoxicity in the forebrain cultures in a concentration-dependent manner. The cytotoxicity was suppressed by preincubation with the selective CB{sub 1} receptor antagonist AM251, but not with the selective CB{sub 2} receptor antagonist AM630. Furthermore, annexin-V-positive cells were found among the treated forebrain cells. Synthetic cannabinoid treatment induced the activation of caspase-3, and preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity. These synthetic cannabinoids induced apoptosis through a caspase-3-dependent mechanism in the forebrain cultures. Our results indicate that the cytotoxicity of synthetic cannabinoids towards primary neuronal cells is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and further suggest that caspase cascades may play an important role in the apoptosis induced by these synthetic cannabinoids. In conclusion, excessive synthetic cannabinoid abuse may present a serious acute health concern due to neuronal damage or deficits in the brain. - Highlights: • Synthetic cannabinoids (classical cannabinoids, non-classical cannabinoids, and aminoalkylindole derivatives) induce cytotoxicity in mouse forebrain cultures. • Synthetic cannabinoid-induced cytotoxicity towards forebrain cultures is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and involves caspase-dependent apoptosis. • A high concentration of synthetic cannabinoids may be toxic to neuronal cells that express CB{sub 1} receptors.

  19. Cannabinoid Receptors in the Central Nervous System: Their Signaling and Roles in Disease

    PubMed Central

    Kendall, Debra A.; Yudowski, Guillermo A.

    2017-01-01

    The identification and cloning of the two major cannabinoid (CB1 and CB2) receptors together with the discovery of their endogenous ligands in the late 80s and early 90s, resulted in a major effort aimed at understanding the mechanisms and physiological roles of the endocannabinoid system (ECS). Due to its expression and localization in the central nervous system (CNS), the CB1 receptor together with its endogenous ligands (endocannabinoids (eCB)) and the enzymes involved in their synthesis and degradation, has been implicated in multiple pathophysiological events ranging from memory deficits to neurodegenerative disorders among others. In this review, we will provide a general overview of the ECS with emphasis on the CB1 receptor in health and disease. We will describe our current understanding of the complex aspects of receptor signaling and trafficking, including the non-canonical signaling pathways such as those mediated by β-arrestins within the context of functional selectivity and ligand bias. Finally, we will highlight some of the disorders in which CB1 receptors have been implicated. Significant knowledge has been achieved over the last 30 years. However, much more research is still needed to fully understand the complex roles of the ECS, particularly in vivo and to unlock its true potential as a source of therapeutic targets. PMID:28101004

  20. Cardiovascular Pharmacology of Cannabinoids

    PubMed Central

    Pacher, P.; Bátkai, S.; Kunos, G.

    2008-01-01

    Cannabinoids and their synthetic and endogenous analogs affect a broad range of physiological functions, including cardiovascular variables, the most important component of their effect being profound hypotension. The mechanisms of the cardiovascular effects of cannabinoids in vivo are complex and may involve modulation of autonomic outflow in both the central and peripheral nervous systems as well as direct effects on the myocardium and vasculature. Although several lines of evidence indicate that the cardiovascular depressive effects of cannabinoids are mediated by peripherally localized CB1 receptors, recent studies provide strong support for the existence of as-yet-undefined endothelial and cardiac receptor(s) that mediate certain endocannabinoid-induced cardiovascular effects. The endogenous cannabinoid system has been recently implicated in the mechanism of hypotension associated with hemorrhagic, endotoxic, and cardiogenic shock, and advanced liver cirrhosis. Furthermore, cannabinoids have been considered as novel antihypertensive agents. A protective role of endocannabinoids in myocardial ischemia has also been documented. In this chapter, we summarize current information on the cardiovascular effects of cannabinoids and highlight the importance of these effects in a variety of pathophysiological conditions. PMID:16596789

  1. Type-1 cannabinoid receptor activity during Alzheimer's disease progression.

    PubMed

    Manuel, Iván; González de San Román, Estíbaliz; Giralt, M Teresa; Ferrer, Isidro; Rodríguez-Puertas, Rafael

    2014-01-01

    The activity of CB1 cannabinoid receptors was studied in postmortem brain samples of Alzheimer's disease (AD) patients during clinical deterioration. CB1 activity was higher at earlier AD stages in limited hippocampal areas and internal layers of frontal cortex, but a decrease was observed at the advanced stages. The pattern of modification appears to indicate initial hyperactivity of the endocannabinoid system in brain areas that lack classical histopathological markers at earlier stages of AD, indicating an attempt to compensate for the initial synaptic impairment, which is then surpassed by disease progression. These results suggest that initial CB1 stimulation might have therapeutic relevance.

  2. CB1 Cannabinoid Receptors and their Associated Proteins

    PubMed Central

    Howlett, Allyn C.; Blume, Lawrence C.; Dalton, George D.

    2011-01-01

    CB1 receptors are G-protein coupled receptors (GPCRs) abundant in neurons, in which they modulate neurotransmission. The CB1 receptor influence on memory and learning is well recognized, and disease states associated with CB1 receptors are observed in addiction disorders, motor dysfunction, schizophrenia, and in bipolar, depression, and anxiety disorders. Beyond the brain, CB1 receptors also function in liver and adipose tissues, vascular as well as cardiac tissue, reproductive tissues and bone. Signal transduction by CB1 receptors occurs through interaction with Gi/o proteins to inhibit adenylyl cyclase, activate mitogen-activated protein kinases (MAPK), inhibit voltage-gated Ca2+ channels, activate K+ currents (Kir), and influence Nitric Oxide (NO) signaling. CB1 receptors are observed in internal organelles as well as plasma membrane. β-Arrestins, adaptor protein AP-3, and G-protein receptor-associated sorting protein 1 (GASP1) modulate cellular trafficking. Cannabinoid Receptor Interacting Protein 1a (CRIP1a) is an accessory protein whose function has not been delineated. Factor Associated with Neutral sphingomyelinase (FAN) regulates ceramide signaling. Such diversity in cellular signaling and modulation by interacting proteins suggests that agonists and allosteric modulators could be developed to specifically regulate unique, cell type-specific responses. PMID:20166926

  3. Endogenous cannabinoids in amygdala and hippocampus in post-mortem brains of Cloninger type 1 and 2 alcoholics.

    PubMed

    Kärkkäinen, Olli K; Lehtonen, Marko; Laukkanen, Virpi; Tupala, Erkki; Hyytiä, Petri; Kautiainen, Hannu; Tiihonen, Jari; Callaway, J C; Storvik, Markus

    2013-08-01

    Accumulating evidence continues to link certain aspects of the endogenous cannabinoid (EC) system with alcohol dependence, negative-reinforcement learning, and the modulation of stress responses. Specific alterations in brain regions that are related to stress and negative-reinforcement learning have been reported to exist in Cloninger type 1 and type 2 alcoholics. To study possible differences in profiles of EC systems between Cloninger type 1 (n = 9) and type 2 (n = 8) alcoholics and non-alcoholic control subjects (n = 10), we analyzed post-mortem amygdala and hippocampus brain samples for several ECs by quantitative liquid chromatography with triple quadrupole mass-spectrometric detection. A significant difference was found between these 3 groups in terms of EC profiles in the amygdala (p = 0.037). In particular, this difference was prominent for variations in docosahexaenoylethanolamide levels, which were significantly higher in type 1 alcoholics (p = 0.022) when compared to controls. There was also a large negative correlation between anandamide concentration and mGlu1/5 receptor density in the hippocampi of Cloninger type 1 alcoholics (R = -0.88, p = 0.002), which was not seen in Cloninger type 2 alcoholics or in controls. Although preliminary, and from relatively small diagnostic groups, these results suggest that the EC system profile may be altered in the hippocampus and amygdala of Cloninger type 1 alcoholics.

  4. Identification of receptors for pig endogenous retrovirus.

    PubMed

    Ericsson, Thomas A; Takeuchi, Yasuhiro; Templin, Christian; Quinn, Gary; Farhadian, Shelli F; Wood, James C; Oldmixon, Beth A; Suling, Kristen M; Ishii, Jennifer K; Kitagawa, Yoshinori; Miyazawa, Takayuki; Salomon, Daniel R; Weiss, Robin A; Patience, Clive

    2003-05-27

    Xenotransplantation of porcine tissues has the potential to treat a wide variety of major health problems including organ failure and diabetes. Balanced against the potential benefits of xenotransplantation, however, is the risk of human infection with a porcine microorganism. In particular, the transmission of porcine endogenous retrovirus (PERV) is a major concern [Chapman, L. E. & Bloom, E. T. (2001) J. Am. Med. Assoc. 285, 2304-2306]. Here we report the identification of two, sequence-related, human proteins that act as receptors for PERV-A, encoded by genes located on chromosomes 8 and 17. We also describe homologs from baboon and porcine cells that also are active as receptors. Conversely, activity could not be demonstrated with a syntenic murine receptor homolog. Sequence analysis indicates that PERV-A receptors [human PERV-A receptor (HuPAR)-1, HuPAR-2, baboon PERV-A receptor 2, and porcine PERV-A receptor] are multiple membrane-spanning proteins similar to receptors for other gammaretroviruses. Expression is widespread in human tissues including peripheral blood mononuclear cells, but their biological functions are unknown. The identification of the PERV-A receptors opens avenues of research necessary for a more complete assessment of the retroviral risks of pig to human xenotransplantation.

  5. Complex pharmacology of natural cannabinoids: evidence for partial agonist activity of delta9-tetrahydrocannabinol and antagonist activity of cannabidiol on rat brain cannabinoid receptors.

    PubMed

    Petitet, F; Jeantaud, B; Reibaud, M; Imperato, A; Dubroeucq, M C

    1998-01-01

    Delta9-tetrahydrocannabinol (delta9-THC), cannabinol and cannabidiol are three important natural cannabinoids from the Marijuana plant (Cannabis sativa). Using [35S]GTP-gamma-S binding on rat cerebellar homogenate as an index of cannabinoid receptor activation we show that: delta9-THC does not induce the maximal effect obtained by classical cannabinoid receptor agonists such as CP55940. Moreover at high concentration delta9-THC exhibits antagonist properties. Cannabinol is a weak agonist on rat cerebellar cannabinoid receptors and cannabidiol behaves as an antagonist acting in the micromolar range.

  6. Modulation of Pilocarpine-Induced Seizures by Cannabinoid Receptor 1

    PubMed Central

    Kow, Rebecca L.; Jiang, Kelly; Naydenov, Alipi V.; Le, Joshua H.; Stella, Nephi; Nathanson, Neil M.

    2014-01-01

    Administration of the muscarinic agonist pilocarpine is commonly used to induce seizures in rodents for the study of epilepsy. Activation of muscarinic receptors has been previously shown to increase the production of endocannabinoids in the brain. Endocannabinoids act at the cannabinoid CB1 receptors to reduce neurotransmitter release and the severity of seizures in several models of epilepsy. In this study, we determined the effect of CB1 receptor activity on the induction in mice of seizures by pilocarpine. We found that decreased activation of the CB1 receptor, either through genetic deletion of the receptor or treatment with a CB1 antagonist, increased pilocarpine seizure severity without modifying seizure-induced cell proliferation and cell death. These results indicate that endocannabinoids act at the CB1 receptor to modulate the severity of pilocarpine-induced seizures. Administration of a CB1 agonist produced characteristic CB1-dependent behavioral responses, but did not affect pilocarpine seizure severity. A possible explanation for the lack of effect of CB1 agonist administration on pilocarpine seizures, despite the effects of CB1 antagonist administration and CB1 gene deletion, is that muscarinic receptor-stimulated endocannabinoid production is acting maximally at CB1 receptors to modulate sensitivity to pilocarpine seizures. PMID:24752144

  7. Cannabinoids attenuate norepinephrine-induced melatonin biosynthesis in the rat pineal gland by reducing arylalkylamine N-acetyltransferase activity without involvement of cannabinoid receptors.

    PubMed

    Koch, Marco; Dehghani, Faramarz; Habazettl, Iris; Schomerus, Christof; Korf, Horst-Werner

    2006-07-01

    Cannabinoids modulate neuronal and neuroendocrine circuits by binding to cannabinoid receptors acting upon cAMP/Ca(2+)-mediated intracellular signaling cascades. The rat pineal represents an established model to investigate intracellular signaling processes because a well defined input, the neurotransmitter norepinephrine, is transformed via cAMP/Ca(2+)-dependent mechanisms into an easily detectable output signal, the biosynthesis of melatonin. Here we investigated the impact of cannabinoids on norepinephrine-regulated melatonin biosynthesis in the rat pineal. We demonstrated that treatment of cultured rat pineals with 9-carboxy-11-nor-delta-9-tetrahydrocannabinol (THC), cannabidiol or cannabinol significantly reduced norepinephrine-induced arylalkylamine N-acetyltransferase (AANAT) activity and melatonin biosynthesis. These effects were not mimicked by the cannabinoid receptor agonist WIN55,212-2 and were not blocked by cannabinoid 1 and 2 receptor antagonists. The cannabinoids used did not affect norepinephrine-induced increases in cAMP/Ca(2+) levels. Notably, cannabinoids were found to directly inhibit AANAT activity in lysates of the pineal gland. This effect was specific in so far as cannabinoids did not influence the activity of hydroxyindole-O-methyltransferase (HIOMT), the last enzyme in melatonin biosynthesis. Taken together, our data strongly suggest that cannabinoids inhibit AANAT activity and attenuate melatonin biosynthesis through intracellular actions without involvement of classical cannabinoid receptor-dependent signaling cascades.

  8. Interaction between the cholecystokinin and endogenous cannabinoid systems in cued fear expression and extinction retention.

    PubMed

    Bowers, Mallory E; Ressler, Kerry J

    2015-02-01

    Post-traumatic stress disorder (PTSD) is thought to develop, in part, from improper inhibition of fear. Accordingly, one of the most effective treatment strategies for PTSD is exposure-based psychotherapy. Ideally, neuroscience would inform adjunct therapies that target the neurotransmitter systems involved in extinction processes. Separate studies have implicated the cholecystokinin (CCK) and endocannabinoid systems in fear; however, there is a high degree of anatomical colocalization between the cannabinoid 1 receptor (Cnr1) and CCK in the basolateral amygdala (BLA), a brain region critical for emotion regulation. Although most research has focused on GABA and GABAergic plasticity as the mechanism by which Cnr1 mediates fear inhibition, we hypothesize that a functional interaction between Cnr1 and CCKB receptor (CCKBR) is critical for fear extinction processes. In this study, systemic pharmacological manipulation of the cannabinoid system modulated cued fear expression in C57BL/6J mice after consolidation of auditory fear conditioning. Knockout of the CCKBR, however, had no effect on fear- or anxiety-like behaviors. Nonetheless, administration of a Cnr1 antagonist increased freezing behavior during a cued fear expression test in wild-type subjects, but had no effect on freezing behavior in CCKBR knockout littermates. In addition, we found that Cnr1-positive fibers form perisomatic clusters around CCKBR-positive cell bodies in the BLA. These CCKBR-positive cells comprise a molecularly heterogenous population of excitatory and inhibitory neurons. These findings provide novel evidence that Cnr1 contributes to cued fear expression via an interaction with the CCK system. Dysfunctional Cnr1-CCKBR interactions might contribute to the etiology of, or result from, fear-related psychiatric disease.

  9. Interaction between the Cholecystokinin and Endogenous Cannabinoid Systems in Cued Fear Expression and Extinction Retention

    PubMed Central

    Bowers, Mallory E; Ressler, Kerry J

    2015-01-01

    Post-traumatic stress disorder (PTSD) is thought to develop, in part, from improper inhibition of fear. Accordingly, one of the most effective treatment strategies for PTSD is exposure-based psychotherapy. Ideally, neuroscience would inform adjunct therapies that target the neurotransmitter systems involved in extinction processes. Separate studies have implicated the cholecystokinin (CCK) and endocannabinoid systems in fear; however, there is a high degree of anatomical colocalization between the cannabinoid 1 receptor (Cnr1) and CCK in the basolateral amygdala (BLA), a brain region critical for emotion regulation. Although most research has focused on GABA and GABAergic plasticity as the mechanism by which Cnr1 mediates fear inhibition, we hypothesize that a functional interaction between Cnr1 and CCKB receptor (CCKBR) is critical for fear extinction processes. In this study, systemic pharmacological manipulation of the cannabinoid system modulated cued fear expression in C57BL/6J mice after consolidation of auditory fear conditioning. Knockout of the CCKBR, however, had no effect on fear- or anxiety-like behaviors. Nonetheless, administration of a Cnr1 antagonist increased freezing behavior during a cued fear expression test in wild-type subjects, but had no effect on freezing behavior in CCKBR knockout littermates. In addition, we found that Cnr1-positive fibers form perisomatic clusters around CCKBR-positive cell bodies in the BLA. These CCKBR-positive cells comprise a molecularly heterogenous population of excitatory and inhibitory neurons. These findings provide novel evidence that Cnr1 contributes to cued fear expression via an interaction with the CCK system. Dysfunctional Cnr1–CCKBR interactions might contribute to the etiology of, or result from, fear-related psychiatric disease. PMID:25176168

  10. Crystal Structure of the Human Cannabinoid Receptor CB1.

    PubMed

    Hua, Tian; Vemuri, Kiran; Pu, Mengchen; Qu, Lu; Han, Gye Won; Wu, Yiran; Zhao, Suwen; Shui, Wenqing; Li, Shanshan; Korde, Anisha; Laprairie, Robert B; Stahl, Edward L; Ho, Jo-Hao; Zvonok, Nikolai; Zhou, Han; Kufareva, Irina; Wu, Beili; Zhao, Qiang; Hanson, Michael A; Bohn, Laura M; Makriyannis, Alexandros; Stevens, Raymond C; Liu, Zhi-Jie

    2016-10-20

    Cannabinoid receptor 1 (CB1) is the principal target of Δ(9)-tetrahydrocannabinol (THC), a psychoactive chemical from Cannabis sativa with a wide range of therapeutic applications and a long history of recreational use. CB1 is activated by endocannabinoids and is a promising therapeutic target for pain management, inflammation, obesity, and substance abuse disorders. Here, we present the 2.8 Å crystal structure of human CB1 in complex with AM6538, a stabilizing antagonist, synthesized and characterized for this structural study. The structure of the CB1-AM6538 complex reveals key features of the receptor and critical interactions for antagonist binding. In combination with functional studies and molecular modeling, the structure provides insight into the binding mode of naturally occurring CB1 ligands, such as THC, and synthetic cannabinoids. This enhances our understanding of the molecular basis for the physiological functions of CB1 and provides new opportunities for the design of next-generation CB1-targeting pharmaceuticals.

  11. Cannabinoid receptor signaling regulates liver development and metabolism.

    PubMed

    Liu, Leah Y; Alexa, Kristen; Cortes, Mauricio; Schatzman-Bone, Stephanie; Kim, Andrew J; Mukhopadhyay, Bani; Cinar, Resat; Kunos, George; North, Trista E; Goessling, Wolfram

    2016-02-15

    Endocannabinoid (EC) signaling mediates psychotropic effects and regulates appetite. By contrast, potential roles in organ development and embryonic energy consumption remain unknown. Here, we demonstrate that genetic or chemical inhibition of cannabinoid receptor (Cnr) activity disrupts liver development and metabolic function in zebrafish (Danio rerio), impacting hepatic differentiation, but not endodermal specification: loss of cannabinoid receptor 1 (cnr1) and cnr2 activity leads to smaller livers with fewer hepatocytes, reduced liver-specific gene expression and proliferation. Functional assays reveal abnormal biliary anatomy and lipid handling. Adult cnr2 mutants are susceptible to hepatic steatosis. Metabolomic analysis reveals reduced methionine content in Cnr mutants. Methionine supplementation rescues developmental and metabolic defects in Cnr mutant livers, suggesting a causal relationship between EC signaling, methionine deficiency and impaired liver development. The effect of Cnr on methionine metabolism is regulated by sterol regulatory element-binding transcription factors (Srebfs), as their overexpression rescues Cnr mutant liver phenotypes in a methionine-dependent manner. Our work describes a novel developmental role for EC signaling, whereby Cnr-mediated regulation of Srebfs and methionine metabolism impacts liver development and function.

  12. Cannabinoid receptor signaling regulates liver development and metabolism

    PubMed Central

    Liu, Leah Y.; Alexa, Kristen; Cortes, Mauricio; Schatzman-Bone, Stephanie; Kim, Andrew J.; Mukhopadhyay, Bani; Cinar, Resat; Kunos, George; North, Trista E.; Goessling, Wolfram

    2016-01-01

    Endocannabinoid (EC) signaling mediates psychotropic effects and regulates appetite. By contrast, potential roles in organ development and embryonic energy consumption remain unknown. Here, we demonstrate that genetic or chemical inhibition of cannabinoid receptor (Cnr) activity disrupts liver development and metabolic function in zebrafish (Danio rerio), impacting hepatic differentiation, but not endodermal specification: loss of cannabinoid receptor 1 (cnr1) and cnr2 activity leads to smaller livers with fewer hepatocytes, reduced liver-specific gene expression and proliferation. Functional assays reveal abnormal biliary anatomy and lipid handling. Adult cnr2 mutants are susceptible to hepatic steatosis. Metabolomic analysis reveals reduced methionine content in Cnr mutants. Methionine supplementation rescues developmental and metabolic defects in Cnr mutant livers, suggesting a causal relationship between EC signaling, methionine deficiency and impaired liver development. The effect of Cnr on methionine metabolism is regulated by sterol regulatory element-binding transcription factors (Srebfs), as their overexpression rescues Cnr mutant liver phenotypes in a methionine-dependent manner. Our work describes a novel developmental role for EC signaling, whereby Cnr-mediated regulation of Srebfs and methionine metabolism impacts liver development and function. PMID:26884397

  13. Cannabinoid receptor-independent actions of the aminoalkylindole WIN 55,212-2 on trigeminal sensory neurons

    PubMed Central

    Price, Theodore J; Patwardhan, Amol; Akopian, Armen N; Hargreaves, Kenneth M; Flores, Christopher M

    2004-01-01

    The prototypical aminoalkylindole cannabinoid WIN 55,212-2 (WIN-2) has been shown to produce antihyperalgesia through a peripheral mechanism of action. However, it is not known whether WIN-2 exerts this action directly via cannabinoid receptors located on primary afferents or if other, perhaps indirect or noncannabinoid, mechanisms are involved. To address this question, we have examined the specific actions of WIN-2 on trigeminal ganglion (TG) neurons in vitro by quantifying its ability to modulate the evoked secretion of the proinflammatory neuropeptide CGRP as well as the inflammatory mediator-induced generation of cAMP. WIN-2 evoked CGRP release from TG neurons in vitro (EC50=26 μM) in a concentration- and calcium-dependent manner, which was mimicked by the cannabinoid receptor-inactive enantiomer WIN 55,212-3 (WIN-3). Moreover, WIN-2-evoked CGRP release was attenuated by the nonselective cation channel blocker ruthenium red but not by the vanilloid receptor type 1 (TRPV1) antagonist capsazepine, suggesting that, unlike certain endogenous and synthetic cannabinoids, WIN-2 is not a TRPV1 agonist but rather acts at an as yet unidentified cation channel. The inhibitory effects of WIN-2 on TG neurons were also examined. WIN-2 neither inhibited capsaicin-evoked CGRP release nor did it inhibit forskolin-, isoproteranol- or prostaglandin E2-stimulated cAMP accumulation. On the other hand, WIN-2 significantly inhibited (EC50=1.7 μM) 50 mM K+-evoked CGRP release by approximately 70%. WIN-2 inhibition of 50 mM K+-evoked CGRP release was not reversed by antagonists of cannabinoid type 1 (CB1) receptor, but was mimicked in magnitude and potency (EC50=2.7 μM) by its cannabinoid-inactive enantiomer WIN-3. These findings indicate that WIN-2 exerts both excitatory and inhibitory effects on TG neurons, neither of which appear to be mediated by CB1, CB2 or TRPV1 receptors, but by a novel calcium-dependent mechanism. The ramifications of these results are discussed in relation

  14. Cannabinoids modulate Olig2 and polysialylated neural cell adhesion molecule expression in the subventricular zone of post-natal rats through cannabinoid receptor 1 and cannabinoid receptor 2.

    PubMed

    Arévalo-Martín, Angel; García-Ovejero, Daniel; Rubio-Araiz, Ana; Gómez, Oscar; Molina-Holgado, Francisco; Molina-Holgado, Eduardo

    2007-09-01

    The subventricular zone (SVZ) is a source of post-natal glial precursors that can migrate to the overlying white matter, where they may differentiate into oligodendrocytes. We showed that, in the post-natal SVZ ependymocytes, radial glia and astrocyte-like cells express cannabinoid receptor 1 (CB1), whereas cannabinoid receptor 2 (CB2) is found in cells expressing the polysialylated neural cell adhesion molecule. To study CB1 and CB2 function, post-natal rats were exposed to selective CB1 or CB2 agonists (arachidonyl-2-chloroethylamide and JWH-056, respectively) for 15 days. Accordingly, we found that CB1 activation increases the number of Olig2-positive cells in the dorsolateral SVZ, whereas CB2 activation increases polysialylated neural cell adhesion molecule expression in this region. As intense myelination occurs during the first weeks of post-natal development, we examined how modulating these factors affected the expression of myelin basic protein. Pharmacological administration of agonists and antagonists of CB1 and CB2 showed that the activation of both receptors is needed to augment the expression of myelin basic protein in the subcortical white matter.

  15. Adolescent brain maturation, the endogenous cannabinoid system and the neurobiology of cannabis-induced schizophrenia.

    PubMed

    Bossong, Matthijs G; Niesink, Raymond J M

    2010-11-01

    Cannabis use during adolescence increases the risk of developing psychotic disorders later in life. However, the neurobiological processes underlying this relationship are unknown. This review reports the results of a literature search comprising various neurobiological disciplines, ultimately converging into a model that might explain the neurobiology of cannabis-induced schizophrenia. The article briefly reviews current insights into brain development during adolescence. In particular, the role of the excitatory neurotransmitter glutamate in experience-dependent maturation of specific cortical circuitries is examined. The review also covers recent hypotheses regarding disturbances in strengthening and pruning of synaptic connections in the prefrontal cortex, and the link with latent psychotic disorders. In the present model, cannabis-induced schizophrenia is considered to be a distortion of normal late postnatal brain maturation. Distortion of glutamatergic transmission during critical periods may disturb prefrontal neurocircuitry in specific brain areas. Our model postulates that adolescent exposure to Δ9-tetrahydrocannabinol (THC), the primary psychoactive substance in cannabis, transiently disturbs physiological control of the endogenous cannabinoid system over glutamate and GABA release. As a result, THC may adversely affect adolescent experience-dependent maturation of neural circuitries within prefrontal cortical areas. Depending on dose, exact time window and duration of exposure, this may ultimately lead to the development of psychosis or schizophrenia. The proposed model provides testable hypotheses which can be addressed in future studies, including animal experiments, reanalysis of existing epidemiological data, and prospective epidemiological studies in which the role of the dose-time-effect relationship should be central.

  16. Brain cannabinoid CB₂ receptors modulate cocaine's actions in mice.

    PubMed

    Xi, Zheng-Xiong; Peng, Xiao-Qing; Li, Xia; Song, Rui; Zhang, Hai-Ying; Liu, Qing-Rong; Yang, Hong-Ju; Bi, Guo-Hua; Li, Jie; Gardner, Eliot L

    2011-07-24

    The presence and function of cannabinoid CB(2) receptors in the brain have been the subjects of much debate. We found that systemic, intranasal or intra-accumbens local administration of JWH133, a selective CB(2) receptor agonist, dose-dependently inhibited intravenous cocaine self-administration, cocaine-enhanced locomotion, and cocaine-enhanced accumbens extracellular dopamine in wild-type and CB(1) receptor knockout (CB(1)(-/-), also known as Cnr1(-/-)) mice, but not in CB(2)(-/-) (Cnr2(-/-)) mice. This inhibition was mimicked by GW405833, another CB(2) receptor agonist with a different chemical structure, and was blocked by AM630, a selective CB(2) receptor antagonist. Intra-accumbens administration of JWH133 alone dose-dependently decreased, whereas intra-accumbens administration of AM630 elevated, extracellular dopamine and locomotion in wild-type and CB(1)(-/-) mice, but not in CB(2)(-/-) mice. Intra-accumbens administration of AM630 also blocked the reduction in cocaine self-administration and extracellular dopamine produced by systemic administration of JWH133. These findings suggest that brain CB(2) receptors modulate cocaine's rewarding and locomotor-stimulating effects, likely by a dopamine-dependent mechanism.

  17. Differential cannabinoid receptor expression during reactive gliosis: a possible implication for a nonpsychotropic neuroprotection.

    PubMed

    De Filippis, Daniele; Steardo, Antonio; D'Amico, Alessandra; Scuderi, Caterina; Cipriano, Mariateresa; Esposito, Giuseppe; Iuvone, Teresa

    2009-03-31

    Activated microglia and astrocytes produce a large number of inflammatory and neurotoxic substances in various brain pathologies, above all during neurodegenerative disorders. In the search for new neuroprotective compounds, interest has turned to marijuana derivatives, since in several in vitro, in vivo, and clinical studies, they have shown a great ability to control neuroinflammation. Despite the emerging evidence regarding pharmacological activities of cannabinoids, their effective introduction into clinical therapy still remains controversial and strongly limited by their unavoidable psychotropicity. Since the psychotropic effect of cannabinoids is generally linked to the activation of the CB1 receptor on neurons, the aim of our review is to clarify the function of the two cannabinoid receptors on glial cells and the differential role played by them, highlighting the emerging evidence of a CB2-mediated control of neuroinflammation that could liberate cannabinoids from the slavery of their central side effects. Despite the emerging evidence regarding pharmacological activities of cannabinoids, however their effective introduction in the clinical therapy remains still controversial and strongly limited by their unavoidable psychotropicity. Since the psychotropic effect of cannabinoids is generally linked to the activation of CB1 receptor on neurons, aim of our review is to clarify the functioning of the two cannabinoid receptors on glial cells and the differential role played by them, highlighting the emerging evidence of a CB2-mediated control of neuro-inflammation that could liberate cannabinoids from the slavery of the central side effects.

  18. Cannabinoids suppress inflammatory and neuropathic pain by targeting α3 glycine receptors.

    PubMed

    Xiong, Wei; Cui, Tanxing; Cheng, Kejun; Yang, Fei; Chen, Shao-Rui; Willenbring, Dan; Guan, Yun; Pan, Hui-Lin; Ren, Ke; Xu, Yan; Zhang, Li

    2012-06-04

    Certain types of nonpsychoactive cannabinoids can potentiate glycine receptors (GlyRs), an important target for nociceptive regulation at the spinal level. However, little is known about the potential and mechanism of glycinergic cannabinoids for chronic pain treatment. We report that systemic and intrathecal administration of cannabidiol (CBD), a major nonpsychoactive component of marijuana, and its modified derivatives significantly suppress chronic inflammatory and neuropathic pain without causing apparent analgesic tolerance in rodents. The cannabinoids significantly potentiate glycine currents in dorsal horn neurons in rat spinal cord slices. The analgesic potency of 11 structurally similar cannabinoids is positively correlated with cannabinoid potentiation of the α3 GlyRs. In contrast, the cannabinoid analgesia is neither correlated with their binding affinity for CB1 and CB2 receptors nor with their psychoactive side effects. NMR analysis reveals a direct interaction between CBD and S296 in the third transmembrane domain of purified α3 GlyR. The cannabinoid-induced analgesic effect is absent in mice lacking the α3 GlyRs. Our findings suggest that the α3 GlyRs mediate glycinergic cannabinoid-induced suppression of chronic pain. These cannabinoids may represent a novel class of therapeutic agents for the treatment of chronic pain and other diseases involving GlyR dysfunction.

  19. Cytotoxicity of synthetic cannabinoids on primary neuronal cells of the forebrain: the involvement of cannabinoid CB1 receptors and apoptotic cell death.

    PubMed

    Tomiyama, Ken-ichi; Funada, Masahiko

    2014-01-01

    The abuse of herbal products containing synthetic cannabinoids has become an issue of public concern. The purpose of this paper was to evaluate the acute cytotoxicity of synthetic cannabinoids on mouse brain neuronal cells. Cytotoxicity induced by synthetic cannabinoid (CP-55,940, CP-47,497, CP-47,497-C8, HU-210, JWH-018, JWH-210, AM-2201, and MAM-2201) was examined using forebrain neuronal cultures. These synthetic cannabinoids induced cytotoxicity in the forebrain cultures in a concentration-dependent manner. The cytotoxicity was suppressed by preincubation with the selective CB1 receptor antagonist AM251, but not with the selective CB2 receptor antagonist AM630. Furthermore, annexin-V-positive cells were found among the treated forebrain cells. Synthetic cannabinoid treatment induced the activation of caspase-3, and preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity. These synthetic cannabinoids induced apoptosis through a caspase-3-dependent mechanism in the forebrain cultures. Our results indicate that the cytotoxicity of synthetic cannabinoids towards primary neuronal cells is mediated by the CB1 receptor, but not by the CB2 receptor, and further suggest that caspase cascades may play an important role in the apoptosis induced by these synthetic cannabinoids. In conclusion, excessive synthetic cannabinoid abuse may present a serious acute health concern due to neuronal damage or deficits in the brain.

  20. Cannabinoid CB1 receptors regulate neuronal TNF-α effects in experimental autoimmune encephalomyelitis.

    PubMed

    Rossi, Silvia; Furlan, Roberto; De Chiara, Valentina; Muzio, Luca; Musella, Alessandra; Motta, Caterina; Studer, Valeria; Cavasinni, Francesca; Bernardi, Giorgio; Martino, Gianvito; Cravatt, Benjamin F; Lutz, Beat; Maccarrone, Mauro; Centonze, Diego

    2011-08-01

    Cannabinoid CB1 receptors (CB1Rs) regulate the neurodegenerative damage of experimental autoimmune encephalomyelitis (EAE) and of multiple sclerosis (MS). The mechanism by which CB1R stimulation exerts protective effects is still unclear. Here we show that pharmacological activation of CB1Rs dampens the tumor necrosis factor α (TNFα)-mediated potentiation of striatal spontaneous glutamate-mediated excitatory postsynaptic currents (EPSCs), which is believed to cogently contribute to the inflammation-induced neurodegenerative damage observed in EAE mice. Furthermore, mice lacking CB1Rs showed a more severe clinical course and, in parallel, exacerbated alterations of sEPSC duration after induction of EAE, indicating that endogenous cannabinoids activate CB1Rs and mitigate the synaptotoxic action of TNFα in EAE. Consistently, we found that mice lacking the fatty acid amide hydrolase (FAAH), and thus expressing abnormally high brain levels of the endocannabinoid anandamide, developed a less severe EAE associated with preserved TNFα-induced sEPSC alterations. CB1Rs are important modulators of EAE pathophysiology, and might play a mechanistic role in the neurodegenerative damage of MS patients.

  1. Cannabinoid CB1 receptors control conditioned drug seeking.

    PubMed

    De Vries, Taco J; Schoffelmeer, Anton N M

    2005-08-01

    Recent developments have implicated cannabinoid CB1 receptors as a novel target for a new class of therapeutic agents used to treat drug addiction. CB1 receptors are expressed in the motivational circuitry of the brain and modulate drug seeking. Blockade of the CB1 receptor is particularly effective in reducing cue-induced reinstatement of drug seeking, an animal analogue of cue-induced relapse in human addicts. These relapse-preventing properties are observed with different classes of abused drug (i.e. psychostimulants, opiates, nicotine and alcohol). In addition, recent evidence indicates a more general role of CB1 receptors in reward-related memories, which is consistent with the proposed role of endocannabinoids in memory-related plasticity. Relapse-preventing actions and inhibitory effects on weight gain were confirmed recently in clinical trials with the CB1 antagonist rimonabant. Collectively, these clinical and preclinical studies suggest that antagonists of CB1 receptors offer a novel approach in the treatment of addictive behaviours.

  2. Predicting the CRIP1a-cannabinoid 1 receptor interactions with integrated molecular modeling approaches

    PubMed Central

    Ahmed, Mostafa H.; Kellogg, Glen E.; Selley, Dana E.; Safo, Martin; Zhang, Yan

    2015-01-01

    Cannabinoid receptors are a family of G-protein coupled receptors that are involved in a wide variety of physiological processes and diseases. One of the key regulators that are unique to cannabinoid receptors is the cannabinoid receptor interacting proteins (CRIPs). Among them CRIP1a was found to decrease the constitutive activity of the cannabinoid type-1 receptor (CB1R). The aim of this study is to gain an understanding of the interaction between CRIP1a and CB1R through using different computational techniques. The generated model demonstrated several key putative interactions between CRIP1a and CB1R, including those involving Lys130 of CRIP1a. PMID:24461351

  3. Pharmacological characterization of the cannabinoid CB₁ receptor PET ligand ortholog, [³H]MePPEP.

    PubMed

    Suter, Todd M; Chesterfield, Amy K; Bao, Chun; Schaus, John M; Krushinski, Joseph H; Statnick, Michael A; Felder, Christian C

    2010-12-15

    MePPEP ((3R,5R)-5-(3-methoxy-phenyl)-3-((R)-1-phenyl-ethylamino)-1-(4-trifluoromethyl-phenyl)-pyrrolidin-2-one) is an inverse agonist shown to be an effective PET ligand for labeling cannabinoid CB₁ receptors in vivo. [¹¹C]MePPEP and structurally related analogs have been reported to specifically and reversibly label cannabinoid CB₁ receptors in rat and non-human primate brains, and [¹¹C]MePPEP has been used in human subjects as a PET tracer. We have generated [³H]MePPEP, an ortholog of [¹¹C]MePPEP, to characterize the molecular pharmacology of the cannabinoid CB₁ receptor across preclinical and clinical species. [³H]MePPEP demonstrates saturable, reversible, and single-site high affinity binding to cannabinoid CB₁ receptors. In cerebellar membranes purified from brains of rat, non-human primate and human, and cells ectopically expressing recombinant human cannabinoid CB₁ receptor, [³H]MePPEP binds cannabinoid CB₁ receptors with similar affinity with K(d) values of 0.09 nM, 0.19 nM, 0.14 nM and 0.16 nM, respectively. Both agonist and antagonist cannabinoid ligands compete [³H]MePPEP with predicted rank order potency. No specific binding is present in autoradiographic sections from cannabinoid CB₁ receptor knockout mouse brains, demonstrating that [³H]MePPEP selectively binds cannabinoid CB₁ receptors in native mouse tissue. Furthermore, [³H]MePPEP binding to anatomical sites in mouse and rat brain is comparable to the anatomical profiles of [¹¹C]MePPEP in non-human primate and human brain in vivo, as well as the binding profiles of other previously described cannabinoid CB₁ receptor agonist and antagonist radioligands. Therefore, [³H]MePPEP is a promising tool for translation of preclinical cannabinoid CB₁ receptor pharmacology to clinical PET ligand and cannabinoid CB₁ receptor inverse agonist therapeutic development.

  4. Endogenous GABAA receptor activity suppresses glioma growth.

    PubMed

    Blanchart, A; Fernando, R; Häring, M; Assaife-Lopes, N; Romanov, R A; Andäng, M; Harkany, T; Ernfors, P

    2017-02-09

    Although genome alterations driving glioma by fueling cell malignancy have largely been resolved, less is known of the impact of tumor environment on disease progression. Here, we demonstrate functional GABAA receptor-activated currents in human glioblastoma cells and show the existence of a continuous GABA signaling within the tumor cell mass that significantly affects tumor growth and survival expectancy in mouse models. Endogenous GABA released by tumor cells, attenuates proliferation of the glioma cells with enriched expression of stem/progenitor markers and with competence to seed growth of new tumors. Our results suggest that GABA levels rapidly increase in tumors impeding further growth. Thus, shunting chloride ions by a maintained local GABAA receptor activity within glioma cells has a significant impact on tumor development by attenuating proliferation, reducing tumor growth and prolonging survival, a mechanism that may have important impact on therapy resistance and recurrence following tumor resection.

  5. CB2 cannabinoid receptor activation promotes colon cancer progression via AKT/GSK3β signaling pathway

    PubMed Central

    Martínez-Martínez, Esther; Martín-Ruiz, Asunción; Martín, Paloma; Calvo, Virginia; Provencio, Mariano; García, José M.

    2016-01-01

    The pharmacological activation of the cannabinoid receptor type 2, CB2, has been shown to elicit anti-tumoral mechanisms in different cancer types. However, little is known about its endogenous role in tumor pathophysiology, and different studies have attributed pro-tumorigenic properties to this receptor. In a previous work, we showed that CB2 expression is a poor prognostic factor in colon cancer patients. Here we report that activation of CB2 with low doses of specific agonists induce cell proliferation and favor the acquisition of aggressive molecular features in colon cancer cells. We show that sub-micromolar concentrations of CB2-specific agonists, JWH-133 and HU-308, promote an increase in cell proliferation rate through the activation of AKT/PKB pathway in colon cancer in vitro and in vivo. AKT activation promotes GSK3β inhibition and thus, a more aggressive cell phenotype with the subsequent elevation of SNAIL levels, E-cadherin degradation and β-catenin delocalization from cell membrane. Taken together, our data show that CB2 activation with sub-micromolar doses of agonists, which could be more similar to endogenous levels of cannabinoids, promote colon cancer progression, implicating that CB2 could have a pro-tumorigenic endogenous role in colon cancer. PMID:27634891

  6. A cannabinoid CB(1) receptor antagonist ameliorates impairment of recognition memory on withdrawal from MDMA (Ecstasy).

    PubMed

    Nawata, Yoko; Hiranita, Takato; Yamamoto, Tsuneyuki

    2010-01-01

    (+/-)-3,4-Methylenedioxymethamphetamine (MDMA, 'Ecstasy') abusers have persistent neuropsychiatric deficits including memory impairments after the cessation of abuse. On the other hand, cannabinoid CB(1) receptors have been implicated in learning/memory, and are highly expressed in the hippocampus, a region of the brain believed to have an important function in certain forms of learning and memory. In this study, we clarified the mechanism underlying the cognitive impairment that develops during MDMA withdrawal from the standpoint of the cannabinoid CB(1) receptors. Mice were administered MDMA (10 mg/kg, i.p.) once a day for 7 days. On the 7th day of withdrawal, a novel object recognition task was performed and the amount of cannabinoid CB(1) receptor protein was measured with western blotting. Recognition performance was impaired on the 7th day of withdrawal. This impairment was blocked by AM251, a cannabinoid CB(1) receptor antagonist, administered 30 min before the training trial or co-administered with MDMA. At this time, the level of cannabinoid CB(1) receptor protein increased significantly in the hippocampus but not the prefrontal cortex or striatum. This increase of CB(1) receptor protein in the hippocampus was also blocked by the co-administration of AM251. Furthermore, CB(1) receptor knockout mice showed no impairment of recognition performance on the withdrawal from MDMA. The impairment of recognition memory during withdrawal from MDMA may result from the activation of cannabinoid CB(1) receptors in the hippocampus.

  7. Striatal adenosine A2A and cannabinoid CB1 receptors form functional heteromeric complexes that mediate the motor effects of cannabinoids.

    PubMed

    Carriba, Paulina; Ortiz, Oskar; Patkar, Kshitij; Justinova, Zuzana; Stroik, Jessica; Themann, Andrea; Müller, Christa; Woods, Anima S; Hope, Bruce T; Ciruela, Francisco; Casadó, Vicent; Canela, Enric I; Lluis, Carme; Goldberg, Steven R; Moratalla, Rosario; Franco, Rafael; Ferré, Sergi

    2007-11-01

    The mechanism of action responsible for the motor depressant effects of cannabinoids, which operate through centrally expressed cannabinoid CB1 receptors, is still a matter of debate. In the present study, we report that CB1 and adenosine A2A receptors form heteromeric complexes in co-transfected HEK-293T cells and rat striatum, where they colocalize in fibrilar structures. In a human neuroblastoma cell line, CB1 receptor signaling was found to be completely dependent on A2A receptor activation. Accordingly, blockade of A2A receptors counteracted the motor depressant effects produced by the intrastriatal administration of a cannabinoid CB1 receptor agonist. These biochemical and behavioral findings demonstrate that the profound motor effects of cannabinoids depend on physical and functional interactions between striatal A2A and CB1 receptors.

  8. Chronic activation of CB2 cannabinoid receptors in the hippocampus increases excitatory synaptic transmission

    PubMed Central

    Kim, Jimok; Li, Yong

    2015-01-01

    The roles of CB1 cannabinoid receptors in regulating neuronal activity have been extensively characterized. Although early studies show that CB1 receptors are present in the nervous system and CB2 cannabinoid receptors are in the immune system, recent evidence indicates that CB2 receptors are also expressed in the brain. Activation or blockade of CB2 receptors in vivo induces neuropsychiatric effects, but the cellular mechanisms of CB2 receptor function are unclear. The aim of this study is to determine how activation of CB2 receptors present in the hippocampus regulates synaptic function. Here, we show that when organotypic cultures of rodent hippocampal slices were treated with a CB2 receptor agonist (JWH133 or GP1a) for 7–10 days, quantal glutamate release became more frequent and spine density was increased via extracellular signal-regulated kinases. Chronic intraperitoneal injection of JWH133 into mice also increased excitatory synaptic transmission. These effects were blocked by a CB2 receptor antagonist (SR144528) or absent from hippocampal slices of CB2 receptor knock-out mice. This study reveals a novel cellular function of CB2 cannabinoid receptors in the hippocampus and provides insights into how cannabinoid receptor subtypes diversify the roles of cannabinoids in the brain. PMID:25504573

  9. Cannabinoid Receptors: A Novel Target for Therapy of Prostate Cancer

    DTIC Science & Technology

    2007-02-01

    Prescribed by ANSI Std. Z39.18 Table of Contents Background.…………………………………………………………….…………4 Body …………………………………………………………………………….....5...establish whether cannabinoid receptors could prove to be useful targets for the treatment of prostate cancer. 4 W81XWH-04-1-0217 Body ...Roperh, I., Huffman, J. W., Ramon, y., Cajal . S., and Guzman, M. (2001) Cancer Res. 61, 5784–5789 7. Casanova,M. L., Blazquez, C.,Martinez-Palacio, J

  10. Cannabinoid Receptors: A Novel Target for Treating Prostate Cancer

    DTIC Science & Technology

    2006-02-01

    1 SF 298……………………………………………………………………………2 Background.…………………………………………………………….………..4 Body ……………………………………………………………………………...5...whether cannabinoid receptors could prove to be useful targets for the treatment of prostate cancer. 4 W81XWH-04-1-0217 Body Specific...Velasco G, Galve- Roperh I, Huffman JW, Ramon y Cajal S, Guzman M. (2001) Cancer Res., 61, 5784- 5789. Sanchez I, Dynlacht BD. (2005). Semin. Cell

  11. The calcium-sensitive Sigma-1 receptor prevents cannabinoids from provoking glutamate NMDA receptor hypofunction: implications in antinociception and psychotic diseases.

    PubMed

    Sánchez-Blázquez, Pilar; Rodríguez-Muñoz, María; Herrero-Labrador, Raquel; Burgueño, Javier; Zamanillo, Daniel; Garzón, Javier

    2014-12-01

    Through the cannabinoid receptor 1 (CB1), the endocannabinoid system plays a physiological role in maintaining the activity of glutamate N-methyl-D-aspartate (NMDA) receptor within harmless limits. The influence of cannabinoids must be proportional to the stimulus in order to prevent NMDAR overactivation or exaggerated hypofunction that may precipitate symptoms of psychosis. In this framework, the recently reported association of CB1s with NMDARs, which mediates the reduction of cannabinoid analgesia promoted by NMDAR antagonism, could also support the precipitation of schizophrenia brought about by the abuse of smoked cannabis, mostly among vulnerable individuals. Accordingly, we have investigated this possibility using neuroprotection and analgesia as reporters of the CB1-NMDAR connection. We found that the Sigma 1 receptor (σ1R) acts as a safety switch, releasing NMDARs from the influence of CB1s and thereby avoiding glutamate hypofunction. In σ1R(-/-) mice the activity of NMDARs increases and cannot be regulated by cannabinoids, and NMDAR antagonism produces no effect on cannabinoid analgesia. In wild-type mice, ligands of the σ1R did not affect the CB1-NMDAR regulatory association, however, experimental NMDAR hypofunction enabled σ1R antagonists to release NMDARs from the negative control of CB1s. Of the σ1R antagonists tested, their order of activity was: S1RA > BD1047 ≫ NE100 = BD1063, although SKF10047, PRE-084 and (+)pentazocine were inactive yet able to abolish the effect of S1RA in this paradigm. Thus, the σ1R controls the extent of CB1-NMDAR interaction and its failure might constitute a vulnerability factor for cannabis abuse, potentially precipitating schizophrenia that might otherwise be induced later in time by the endogenous system.

  12. Inhibition of the production of endothelium-derived hyperpolarizing factor by cannabinoid receptor agonists

    PubMed Central

    Fleming, I; Schermer, B; Popp, R; Busse, R

    1999-01-01

    The endogenous cannabinoid, anandamide, has been reported to induce an 'endothelium-derived hyperpolarizing factor (EDHF)-like' relaxation in vitro. We therefore investigated the effects of cannabinoid CB1 receptor agonists; HU 210, Δ9-tetrahydrocannabinol (Δ9-THC) and anandamide, and a CB1 antagonist/inverse agonist, SR 141716A, on nitric oxide (NO) and EDHF-mediated relaxation in precontracted rings of porcine coronary, rabbit carotid and mesenteric arteries. In rings of mesenteric artery HU 210 and Δ9-THC induced endothelium- and cyclo-oxygenase-independent relaxations which were sensitive to SR 141716A. Anandamide (0.03–30 μM) induced a slowly developing, endothelium-independent relaxation which was abolished by diclofenac and was therefore mediated by cyclo-oxygenase product(s). None of the CB1 agonists tested affected the tone of precontracted rings of rabbit carotid or porcine coronary artery. In endothelium-intact segments, HU 210, Δ9-THC and anandamide did not affect NO-mediated responses but under conditions of continuous NO synthase/cyclo-oxygenase blockade, significantly inhibited acetylcholine and bradykinin-induced relaxations which are attributed to the production of EDHF. The effects of HU 210 and Δ9-THC were not observed when experiments were performed in the presence of SR 141716A suggesting the involvement of the CB1 receptor. In a patch clamp bioassay of EDHF production, HU 210 decreased the EDHF-mediated hyperpolarization of detector smooth muscle cells when applied to the donor segment but was without effect on the membrane potential of detector cells. The inhibition of EDHF production was unrelated to alterations in Ca2+-signalling or cytochrome P450 activity. These results suggest that the activation of endothelial CB1 receptors appears to be negatively coupled to the production of EDHF. PMID:10193775

  13. Post-natal development of type 1 cannabinoid receptor immunoreactivity in the rat hippocampus.

    PubMed

    Morozov, Yury M; Freund, Tamás F

    2003-09-01

    Type 1 cannabinoid receptors, selectively located on axon terminals of GABAergic interneurons in the hippocampus, are known to be involved in endocannabinoid-mediated retrograde synaptic signalling. The question arises whether type 1 cannabinoid receptors appear on these axons during early post-natal life, when GABAergic transmission is still depolarizing, and whether there are any developmental changes in the cellular or subcellular expression pattern. Here we demonstrate, using single and double immunocytochemical methods at the light and electron microscopic levels, that type 1 cannabinoid receptors are expressed only on the membrane of axon terminals and pre-terminal axons but not on the soma-dendritic membrane at all examined timepoints between post-natal days 0 and 20, similar to the adult distribution. All type 1 cannabinoid receptor-positive boutons formed symmetric synapses. Granular labelling in the somata was already strong at post-natal day 0 and corresponded to multivesicular bodies, lysosomes, Golgi apparatus and rough endoplasmic reticulum. The type 1 cannabinoid receptor-positive axons were shown to originate largely from cholecystokinin-immunoreactive basket and bistratified neurons throughout the hippocampus (90% of all type 1 cannabinoid receptor-containing cells) and dentate gyrus (70% of all type 1 cannabinoid receptor-containing cells). The remaining cells have not been identified but probably belong to the somatostatin- and/or neuropeptide Y-containing subsets, as cholecystokinin-negative, type 1 cannabinoid receptor-positive axons have been observed in strata moleculare and lacunosum-moleculare of the dentate gyrus and CA1-3, respectively, where these neurons are known to arborize. No cell types were found that expressed type 1 cannabinoid receptors transiently at some developmental stage. We conclude that the cellular and subcellular pattern of type 1 cannabinoid receptor expression during early post-natal life is similar to the adult

  14. Endogenous modulators of synaptic transmission: cannabinoid regulation in the supraoptic nucleus.

    PubMed

    McDonald, Neil A; Kuzmiski, J Brent; Naderi, Nima; Schwab, Yannick; Pittman, Quentin J

    2008-01-01

    The magnocellular neurons of the hypothalamic supraoptic nucleus (SON) are a major source of both systemic and central release of the neurohypophyseal peptides, oxytocin (OXT) and arginine-vasopressin (AVP). Both OXT and AVP are released from the somatodendritic compartment of magnocellular neurons and act within the SON to modulate the electrophysiological function of these cells. Cannabinoids (CBs) affect hormonal output and the SON may represent a neural substrate through which CBs exert specific physiological and behavioural effects. Dynamic modulation of synaptic inputs is a fundamental mechanism through which neuronal output is controlled. Dendritically released OXT acts on autoreceptors to generate endocannabinoids (eCBs) which modify both excitatory and inhibitory inputs to OXT neurons through actions on presynaptic CB receptors. As such, OXT and eCBs cooperate to shape the electrophysiological properties of magnocellular OXT neurons, regulating the physiological function of this nucleus. Further study of eCB signalling in the SON, including its interaction with AVP neurons, promises to extend our understanding of the synaptic regulation of SON physiological function.

  15. Cannabinoid receptor ligands suppress memory-related effects of nicotine in the elevated plus maze test in mice.

    PubMed

    Biala, Grazyna; Kruk, Marta

    2008-10-10

    The purpose of the experiments was to examine the memory-related effects of nicotine using the mouse elevated plus maze. It has been shown that the acute doses of nicotine (0.1 and 0.5 mg/kg) significantly decreased the time of transfer latency (TL2) on the retention trial, indicating that nicotine improved memory processes. Similarly, acute doses of the CB1 cannabinoid receptor antagonist AM 251 (0.5, 1, 1.5 and 3 mg/kg) significantly decreased TL2 values. WIN55,212-2, a non-selective CB cannabinoid receptor agonist, at any dose tested (0.25, 0.5 and 1 mg/kg), did not provoke any effect in this model. Moreover, the acute injection of both WIN55,212-2 (0.25 and 0.5 mg/kg) and AM 251 (0.25 mg/kg), prior to injections of nicotine (0.1 and 0.5 mg/kg), significantly prevented nicotine-induced memory improvement. The results of this study provide clear evidence that the endogenous cannabinoid system participates in the responses induced by nicotine on memory-related behaviour in mice.

  16. The cannabinoid beta-caryophyllene (BCP) induces neuritogenesis in PC12 cells by a cannabinoid-receptor-independent mechanism.

    PubMed

    Santos, Neife Aparecida Guinaim; Martins, Nádia Maria; Sisti, Flávia Malvestio; Fernandes, Laís Silva; Ferreira, Rafaela Scalco; de Freitas, Osvaldo; Santos, Antônio Cardozo

    2017-01-05

    Beta-caryophyllene (BCP) is a phytocannabinoid whose neuroprotective activity has been mainly associated with selective activation of cannabinoid-type-2 (CB2) receptors, inhibition of microglial activation and decrease of inflammation. Here, we addressed the potential of BCP to induce neuritogenesis in PC12 cells, a model system for primary neuronal cells that express trkA receptors, respond to NGF and do not express CB2 receptors. We demonstrated that BCP increases the survival and activates the NGF-specific receptor trkA in NGF-deprived PC12 cells, without increasing the expression of NGF itself. The neuritogenic effect of BCP in PC12 cells was abolished by k252a, an inhibitor of the NGF-specific receptor trkA. Accordingly, BCP did not induce neuritogenesis in SH-SY5Y neuroblastoma cells, a neuronal model that does not express trkA receptors and do not respond to NGF. Additionally, we demonstrated that BCP increases the expression of axonal-plasticity-associated proteins (GAP-43, synapsin and synaptophysin) in PC12 cells. It is known that these proteins are up-regulated by NGF in neurons and neuron-like cells, such as PC12 cells. Altogether, these findings suggest that BCP activates trka receptors and induces neuritogenesis by a mechanism independent of NGF or cannabinoid receptors. This is the first study to show such effects of BCP and their beneficial role in neurodegenerative processes should be further investigated.

  17. CB2 cannabinoid receptor agonist enantiomers HU-433 and HU-308: An inverse relationship between binding affinity and biological potency.

    PubMed

    Smoum, Reem; Baraghithy, Saja; Chourasia, Mukesh; Breuer, Aviva; Mussai, Naama; Attar-Namdar, Malka; Kogan, Natalya M; Raphael, Bitya; Bolognini, Daniele; Cascio, Maria G; Marini, Pietro; Pertwee, Roger G; Shurki, Avital; Mechoulam, Raphael; Bab, Itai

    2015-07-14

    Activation of the CB2 receptor is apparently an endogenous protective mechanism. Thus, it restrains inflammation and protects the skeleton against age-related bone loss. However, the endogenous cannabinoids, as well as Δ(9)-tetrahydrocannabinol, the main plant psychoactive constituent, activate both cannabinoid receptors, CB1 and CB2. HU-308 was among the first synthetic, selective CB2 agonists. HU-308 is antiosteoporotic and antiinflammatory. Here we show that the HU-308 enantiomer, designated HU-433, is 3-4 orders of magnitude more potent in osteoblast proliferation and osteoclast differentiation culture systems, as well as in mouse models, for the rescue of ovariectomy-induced bone loss and ear inflammation. HU-433 retains the HU-308 specificity for CB2, as shown by its failure to bind to the CB1 cannabinoid receptor, and has no activity in CB2-deficient cells and animals. Surprisingly, the CB2 binding affinity of HU-433 in terms of [(3)H]CP55,940 displacement and its effect on [(35)S]GTPγS accumulation is substantially lower compared with HU-308. A molecular-modeling analysis suggests that HU-433 and -308 have two different binding conformations within CB2, with one of them possibly responsible for the affinity difference, involving [(35)S]GTPγS and cAMP synthesis. Hence, different ligands may have different orientations relative to the same binding site. This situation questions the usefulness of universal radioligands for comparative binding studies. Moreover, orientation-targeted ligands have promising potential for the pharmacological activation of distinct processes.

  18. CB2 cannabinoid receptor agonist enantiomers HU-433 and HU-308: An inverse relationship between binding affinity and biological potency

    PubMed Central

    Smoum, Reem; Baraghithy, Saja; Chourasia, Mukesh; Breuer, Aviva; Mussai, Naama; Attar-Namdar, Malka; Kogan, Natalya M.; Raphael, Bitya; Bolognini, Daniele; Cascio, Maria G.; Marini, Pietro; Pertwee, Roger G.; Shurki, Avital; Mechoulam, Raphael; Bab, Itai

    2015-01-01

    Activation of the CB2 receptor is apparently an endogenous protective mechanism. Thus, it restrains inflammation and protects the skeleton against age-related bone loss. However, the endogenous cannabinoids, as well as Δ9-tetrahydrocannabinol, the main plant psychoactive constituent, activate both cannabinoid receptors, CB1 and CB2. HU-308 was among the first synthetic, selective CB2 agonists. HU-308 is antiosteoporotic and antiinflammatory. Here we show that the HU-308 enantiomer, designated HU-433, is 3–4 orders of magnitude more potent in osteoblast proliferation and osteoclast differentiation culture systems, as well as in mouse models, for the rescue of ovariectomy-induced bone loss and ear inflammation. HU-433 retains the HU-308 specificity for CB2, as shown by its failure to bind to the CB1 cannabinoid receptor, and has no activity in CB2-deficient cells and animals. Surprisingly, the CB2 binding affinity of HU-433 in terms of [3H]CP55,940 displacement and its effect on [35S]GTPγS accumulation is substantially lower compared with HU-308. A molecular-modeling analysis suggests that HU-433 and -308 have two different binding conformations within CB2, with one of them possibly responsible for the affinity difference, involving [35S]GTPγS and cAMP synthesis. Hence, different ligands may have different orientations relative to the same binding site. This situation questions the usefulness of universal radioligands for comparative binding studies. Moreover, orientation-targeted ligands have promising potential for the pharmacological activation of distinct processes. PMID:26124120

  19. Lack of positive allosteric modulation of mutated alpha(1)S267I glycine receptors by cannabinoids.

    PubMed

    Foadi, Nilufar; Leuwer, Martin; Demir, Reyhan; Dengler, Reinhard; Buchholz, Vanessa; de la Roche, Jeanne; Karst, Matthias; Haeseler, Gertrud; Ahrens, Jörg

    2010-05-01

    Loss of inhibitory synaptic transmission within the dorsal horn of the spinal cord plays a key role in the development of chronic pain following inflammation or nerve injury. Inhibitory postsynaptic transmission in the adult spinal cord involves mainly glycine. Ajulemic acid and HU210 are non-psychotropic, synthetic cannabinoids. Cannabidiol is a non-psychotropic plant constituent of cannabis sativa. There are hints that non-cannabinoid receptor mechanisms of these cannabinoids might be mediated via glycine receptors. In this study, we investigated the impact of the amino acid residue serine at position 267 on the glycine-modulatory effects of ajulemic acid, cannabidiol and HU210. Mutated alpha(1)S267I glycine receptors transiently expressed in HEK293 cells were studied by utilising the whole-cell clamp technique. The mutation of the alpha(1) subunit TM2 serine residue to isoleucine abolished the co-activation and the direct activation of the glycine receptor by the investigated cannabinoids. The nature of the TM2 (267) residue of the glycine alpha(1) subunit is crucial for the glycine-modulatory effect of ajulemic acid, cannabidiol and HU210. An investigation of the impact of such mutations on the in vivo interaction of cannabinoids with glycine receptors should permit a better understanding of the molecular determinants of action of cannabinoids.

  20. Presynaptic TRPV1 vanilloid receptor function is age- but not CB1 cannabinoid receptor-dependent in the rodent forebrain.

    PubMed

    Köles, László; Garção, Pedro; Zádori, Zoltán S; Ferreira, Samira G; Pinheiro, Bárbara S; da Silva-Santos, Carla S; Ledent, Catherine; Köfalvi, Attila

    2013-08-01

    Neocortical and striatal TRPV1 (vanilloid or capsaicin) receptors (TRPV1Rs) are excitatory ligand-gated ion channels, and are implicated in psychiatric disorders. However, the purported presynaptic neuromodulator role of TRPV1Rs in glutamatergic, serotonergic or dopaminergic terminals of the rodent forebrain remains little understood. With the help of patch-clamp electrophysiology and neurochemical approaches, we mapped the age-dependence of presynaptic TRPV1R function, and furthermore, we aimed at exploring whether the presence of CB1 cannabinoid receptors (CB1Rs) influences the function of the TRPV1Rs, as both receptor types share endogenous ligands. We found that the major factor which affects presynaptic TRPV1R function is age: by post-natal day 13, the amplitude of capsaicin-induced release of dopamine and glutamate is halved in the rat striatum, and two weeks later, capsaicin already loses its effect. However, TRPV1R receptor function is not enhanced by chemical or genetic ablation of the CB1Rs in dopaminergic, glutamatergic and serotonergic terminals of the mouse brain. Altogether, our data indicate a possible neurodevelopmental role for presynaptic TRPV1Rs in the rodent brain, but we found no cross-talk between TRPV1Rs and CB1Rs in the same nerve terminal.

  1. Brain cannabinoid receptor 2: expression, function and modulation.

    PubMed

    Chen, De-Jie; Gao, Ming; Gao, Fen-Fei; Su, Quan-Xi; Wu, Jie

    2017-03-01

    Cannabis sativa (marijuana) is a fibrous flowering plant that produces an abundant variety of molecules, some with psychoactive effects. At least 4% of the world's adult population uses cannabis annually, making it one of the most frequently used illicit drugs in the world. The psychoactive effects of cannabis are mediated primarily through cannabinoid receptor (CBR) subtypes. The prevailing view is that CB1Rs are mainly expressed in the central neurons, whereas CB2Rs are predominantly expressed in peripheral immune cells. However, this traditional view has been challenged by emerging strong evidence that shows CB2Rs are moderately expressed and function in specific brain areas. New evidence has demonstrated that brain CB2Rs modulate animal drug-seeking behaviors, suggesting that these receptors may exist in brain regions that regulate drug addiction. Recently, we further confirmed that functional CB2Rs are expressed in mouse ventral tegmental area (VTA) dopamine (DA) neurons and that the activation of VTA CB2Rs reduces neuronal excitability and cocaine-seeking behavior. In addition, CB2R-mediated modulation of hippocampal CA3 neuronal excitability and network synchronization has been reported. Here, we briefly summarize recent lines of evidence showing how CB2Rs modulate function and pathophysiology in the CNS.

  2. Brain cannabinoid receptor 2: expression, function and modulation

    PubMed Central

    Chen, De-jie; Gao, Ming; Gao, Fen-fei; Su, Quan-xi; Wu, Jie

    2017-01-01

    Cannabis sativa (marijuana) is a fibrous flowering plant that produces an abundant variety of molecules, some with psychoactive effects. At least 4% of the world's adult population uses cannabis annually, making it one of the most frequently used illicit drugs in the world. The psychoactive effects of cannabis are mediated primarily through cannabinoid receptor (CBR) subtypes. The prevailing view is that CB1Rs are mainly expressed in the central neurons, whereas CB2Rs are predominantly expressed in peripheral immune cells. However, this traditional view has been challenged by emerging strong evidence that shows CB2Rs are moderately expressed and function in specific brain areas. New evidence has demonstrated that brain CB2Rs modulate animal drug-seeking behaviors, suggesting that these receptors may exist in brain regions that regulate drug addiction. Recently, we further confirmed that functional CB2Rs are expressed in mouse ventral tegmental area (VTA) dopamine (DA) neurons and that the activation of VTA CB2Rs reduces neuronal excitability and cocaine-seeking behavior. In addition, CB2R-mediated modulation of hippocampal CA3 neuronal excitability and network synchronization has been reported. Here, we briefly summarize recent lines of evidence showing how CB2Rs modulate function and pathophysiology in the CNS. PMID:28065934

  3. Cytotoxicity of synthetic cannabinoids found in "Spice" products: the role of cannabinoid receptors and the caspase cascade in the NG 108-15 cell line.

    PubMed

    Tomiyama, Kenichi; Funada, Masahiko

    2011-11-10

    The worldwide distribution of "Spice" that contains synthetic cannabinoids with a pharmacological activity similar to Δ⁹-tetrahydrocannabinol has been reported. In the current study, we evaluated the cytotoxicity of the synthetic cannabinoids, CP-55,940, CP-47,497 and CP-47,497-C8 towards NG 108-15 cells and investigated their mechanism of cytotoxicity. CP-55,940, CP-47,497 and CP-47,497-C8 were all cytotoxic for NG 108-15 cells in a concentration-dependent manner. The cytotoxicity of these synthetic cannabinoids was suppressed by preincubation with the selective CB₁ receptor antagonist AM251, but not with the selective CB₂ receptor antagonist AM630. Preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity of these synthetic cannabinoids for NG 108-15 cells. Induction of apoptosis by these cannabinoids was also confirmed by staining of the cells with annexin V. Our results indicate that the cytotoxicity of synthetic cannabinoids towards NG 108-15 cells is mediated by the CB₁ receptor, but not by the CB₂ receptor, and further suggest that caspase-cascades may play an important role in the apoptosis induced by these synthetic cannabinoids.

  4. Agonist-dependent cannabinoid receptor signalling in human trabecular meshwork cells

    PubMed Central

    McIntosh, B T; Hudson, B; Yegorova, S; Jollimore, C A B; Kelly, M E M

    2007-01-01

    Background and purpose: Trabecular meshwork (TM) is an ocular tissue involved in the regulation of aqueous humour outflow and intraocular pressure (IOP). CB1 receptors (CB1) are present in TM and cannabinoid administration decreases IOP. CB1 signalling was investigated in a cell line derived from human TM (hTM). Experimental approach: CB1 signalling was investigated using ratiometric Ca2+ imaging, western blotting and infrared In-Cell Western analysis. Key results: WIN55212-2, a synthetic aminoalkylindole cannabinoid receptor agonist (10–100 μM) increased intracellular Ca2+ in hTM cells. WIN55,212-2-mediated Ca2+ increases were blocked by AM251, a CB1 antagonist, but were unaffected by the CB2 antagonist, AM630. The WIN55,212-2-mediated increase in [Ca2+]i was pertussis toxin (PTX)-insensitive, therefore, independent of Gi/o coupling, but was attenuated by a dominant negative Gαq/11 subunit, implicating a Gq/11 signalling pathway. The increase in [Ca2+]i was dependent upon PLC activation and mobilization of intracellular Ca2+ stores. A PTX-sensitive increase in extracellular signal-regulated kinase (ERK1/2) phosphorylation was also observed in response to WIN55,212-2, indicative of a Gi/o signalling pathway. CB1-Gq/11 coupling to activate PLC-dependent increases in Ca2+ appeared to be specific to WIN55,212-2 and were not observed with other CB1 agonists, including CP55,940 and methanandamide. CP55940 produced PTX-sensitive increases in [Ca2+]i at concentrations ≥15 μM, and PTX-sensitive increases in ERK1/2 phosphorylation. Conclusions and implications: This study demonstrates that endogenous CB1 couples to both Gq/11 and Gi/o in hTM cells in an agonist-dependent manner. Cannabinoid activation of multiple CB1 signalling pathways in TM tissue could lead to differential changes in aqueous humour outflow and IOP. PMID:17922024

  5. Cannabinoid Receptors Are Overexpressed in CLL but of Limited Potential for Therapeutic Exploitation

    PubMed Central

    Le, Trang; Gruber, Michaela; Pausz, Clemens; Staber, Philipp; Jäger, Ulrich; Vanura, Katrina

    2016-01-01

    The cannabinoid receptors 1 and 2 (CNR1&2) are overexpressed in a variety of malignant diseases and cannabinoids can have noteworthy impact on tumor cell viability and tumor growth. Patients diagnosed with chronic lymphocytic leukemia (CLL) present with very heterogeneous disease characteristics translating into highly differential risk properties. To meet the urgent need for refinement in risk stratification at diagnosis and the search for novel therapies we studied CNR expression and response to cannabinoid treatment in CLL. Expression levels of CNR1&2 were determined in 107 CLL patients by real-time PCR and analyzed with regard to prognostic markers and survival. Cell viability of primary CLL cells was determined in suspension and co-culture after incubation in increasing cannabinoid concentrations under normal and reduced serum conditions and in combination with fludarabine. Impact of cannabinoids on migration of CLL cells towards CXCL12 was determined in transwell plates. We found CNR1&2 to be overexpressed in CLL compared to healthy B-cells. Discriminating between high and low expressing subgroups, only high CNR1 expression was associated with two established high risk markers and conferred significantly shorter overall and treatment free survival. Viability of CLL primary cells was reduced in a dose dependent fashion upon incubation with cannabinoids, however, healthy cells were similarly affected. Under serum reduced conditions, no significant differences were observed within suspension and co-culture, respectively, however, the feeder layer contributed significantly to the survival of CLL cells compared to suspension culture conditions. No significant differences were observed when treating CLL cells with cannabinoids in combination with fludarabine. Interestingly, biologic activity of cannabinoids was independent of both CNR1&2 expression. Finally, we did not observe an inhibition of CXCL12-induced migration by cannabinoids. In contrast to other tumor

  6. The endocannabinoid system and rimonabant: a new drug with a novel mechanism of action involving cannabinoid CB1 receptor antagonism--or inverse agonism--as potential obesity treatment and other therapeutic use.

    PubMed

    Xie, S; Furjanic, M A; Ferrara, J J; McAndrew, N R; Ardino, E L; Ngondara, A; Bernstein, Y; Thomas, K J; Kim, E; Walker, J M; Nagar, S; Ward, S J; Raffa, R B

    2007-06-01

    There is considerable evidence that the endocannabinoid (endogenous cannabinoid) system plays a significant role in appetitive drive and associated behaviours. It is therefore reasonable to hypothesize that the attenuation of the activity of this system would have therapeutic benefit in treating disorders that might have a component of excess appetitive drive or over-activity of the endocannabinoid system, such as obesity, ethanol and other drug abuse, and a variety of central nervous system and other disorders. Towards this end, antagonists of cannabinoid receptors have been designed through rational drug discovery efforts. Devoid of the abuse concerns that confound and impede the use of cannabinoid receptor agonists for legitimate medical purposes, investigation of the use of cannabinoid receptor antagonists as possible pharmacotherapeutic agents is currently being actively investigated. The compound furthest along this pathway is rimonabant, a selective CB(1) (cannabinoid receptor subtype 1) antagonist, or inverse agonist, approved in the European Union and under regulatory review in the United States for the treatment of obesity. This article summarizes the basic science of the endocannabinoid system and the therapeutic potential of cannabinoid receptor antagonists, with emphasis on the treatment of obesity.

  7. Spatial Distribution of the Cannabinoid Type 1 and Capsaicin Receptors May Contribute to the Complexity of Their Crosstalk

    PubMed Central

    Chen, Jie; Varga, Angelika; Selvarajah, Srikumaran; Jenes, Agnes; Dienes, Beatrix; Sousa-Valente, Joao; Kulik, Akos; Veress, Gabor; Brain, Susan D.; Baker, David; Urban, Laszlo; Mackie, Ken; Nagy, Istvan

    2016-01-01

    The cannabinoid type 1 (CB1) receptor and the capsaicin receptor (TRPV1) exhibit co-expression and complex, but largely unknown, functional interactions in a sub-population of primary sensory neurons (PSN). We report that PSN co-expressing CB1 receptor and TRPV1 form two distinct sub-populations based on their pharmacological properties, which could be due to the distribution pattern of the two receptors. Pharmacologically, neurons respond either only to capsaicin (COR neurons) or to both capsaicin and the endogenous TRPV1 and CB1 receptor ligand anandamide (ACR neurons). Blocking or deleting the CB1 receptor only reduces both anandamide- and capsaicin-evoked responses in ACR neurons. Deleting the CB1 receptor also reduces the proportion of ACR neurons without any effect on the overall number of capsaicin-responding cells. Regarding the distribution pattern of the two receptors, neurons express CB1 and TRPV1 receptors either isolated in low densities or in close proximity with medium/high densities. We suggest that spatial distribution of the CB1 receptor and TRPV1 contributes to the complexity of their functional interaction. PMID:27653550

  8. Spatial Distribution of the Cannabinoid Type 1 and Capsaicin Receptors May Contribute to the Complexity of Their Crosstalk.

    PubMed

    Chen, Jie; Varga, Angelika; Selvarajah, Srikumaran; Jenes, Agnes; Dienes, Beatrix; Sousa-Valente, Joao; Kulik, Akos; Veress, Gabor; Brain, Susan D; Baker, David; Urban, Laszlo; Mackie, Ken; Nagy, Istvan

    2016-09-22

    The cannabinoid type 1 (CB1) receptor and the capsaicin receptor (TRPV1) exhibit co-expression and complex, but largely unknown, functional interactions in a sub-population of primary sensory neurons (PSN). We report that PSN co-expressing CB1 receptor and TRPV1 form two distinct sub-populations based on their pharmacological properties, which could be due to the distribution pattern of the two receptors. Pharmacologically, neurons respond either only to capsaicin (COR neurons) or to both capsaicin and the endogenous TRPV1 and CB1 receptor ligand anandamide (ACR neurons). Blocking or deleting the CB1 receptor only reduces both anandamide- and capsaicin-evoked responses in ACR neurons. Deleting the CB1 receptor also reduces the proportion of ACR neurons without any effect on the overall number of capsaicin-responding cells. Regarding the distribution pattern of the two receptors, neurons express CB1 and TRPV1 receptors either isolated in low densities or in close proximity with medium/high densities. We suggest that spatial distribution of the CB1 receptor and TRPV1 contributes to the complexity of their functional interaction.

  9. Novel adamantyl cannabinoids as CB1 receptor probes.

    PubMed

    Thakur, Ganesh A; Bajaj, Shama; Paronis, Carol; Peng, Yan; Bowman, Anna L; Barak, Lawrence S; Caron, Marc G; Parrish, Demon; Deschamps, Jeffrey R; Makriyannis, Alexandros

    2013-05-23

    In previous studies, compound 1 (AM411), a 3-(1-adamantyl) analogue of the phytocannabinoid (-)-Δ(8)-tetrahydrocannabinol (Δ(8)-THC), was shown to have improved affinity and selectivity for the CB1 receptor. In this work, we further explored the role of the 1-adamantyl group at the C-3 position in a series of tricyclic cannabinoid analogues modified at the 9-northern aliphatic hydroxyl (NAH) position. Of these, 9-hydroxymethyl hexahydrocannabinol 11 (AM4054) exhibited high CB1 affinity and full agonist profile. In the cAMP assay, the 9-hydroxymethyl cannabinol analogue 24 (AM4089) had a partial agonist profile, with high affinity and moderate selectivity for rCB1 over hCB2. In vivo results in rat models of hypothermia and analgesia were congruent with in vitro data. Our in vivo data indicate that 3-(1-adamantyl) substitution, within NAH cannabinergics, imparts improved pharmacological profiles when compared to the corresponding, traditionally used 3-dimethylheptyl analogues and identifies 11 and 24 as potentially useful in vivo CB1 cannabinergic probes.

  10. Cannabinoid receptor 2 protects against acute experimental sepsis in mice.

    PubMed

    Gui, Huan; Sun, Yang; Luo, Zhu-Min; Su, Ding-Feng; Dai, Sheng-Ming; Liu, Xia

    2013-01-01

    The systemic inflammatory response syndrome can be self-limited or can progress to severe sepsis and septic shock. Despite significant advances in the understanding of the molecular and cellular mechanisms of septic shock, it is still one of the most frequent and serious problems confronting clinicians in the treatments. And the effects of cannabinoid receptor 2 (CB2R) on the sepsis still remain undefined. The present study was aimed to explore the role and mechanism of CB2R in acute sepsis model of mice. Here, we found that mice were more vulnerable for lipopolysaccharide- (LPS-) induced death and inflammation after CB2R deletion (CB2R(-/-)). CB2R agonist, GW405833, could significantly extend the survival rate and decrease serum proinflammatory cytokines in LPS-treated mice. GW405833 dose-dependently inhibits proinflammatory cytokines release in splenocytes and peritoneal macrophages as well as splenocytes proliferation, and these effects were partly abolished in CB2R(-/-) splenocytes but completely abolished in CB2R(-/-) peritoneal macrophages. Further studies showed that GW405833 inhibits LPS-induced phosphorylation of ERK1/2 and STAT3 and blocks I κ B α degradation and NF- κB p65 nuclear translocation in macrophages. All data together showed that CB2R provides a protection and is a potential therapeutic target for the sepsis.

  11. β-caryophyllene ameliorates cisplatin-induced nephrotoxicity in a cannabinoid 2 receptor-dependent manner

    PubMed Central

    Horváth, Béla; Mukhopadhyay, Partha; Kechrid, Malek; Patel, Vivek; Tanashian, Galin; Wink, David A.; Gertsch, Jürg; Pacher, Pál

    2012-01-01

    (E)-β-caryophyllene (BCP) is a natural sequiterpene found in many essential oils of spice (best known for contributing to the spiciness of black pepper) and food plants with recognized anti-inflammatory properties. Recently it was shown that BCP is a natural agonist of endogenous cannabinoid 2 (CB2) receptors, which are expressed in immune cells and mediate anti-inflammatory effects. In this study we aimed to test the effects of BCP in a clinically relevant murine model of nephropathy (induced by the widely used antineoplastic drug cisplatin) in which the tubular injury is largely dependent on inflammation and oxidative/nitrative stress. β-caryophyllene dose-dependently ameliorated cisplatin-induced kidney dysfunction, morphological damage, and renal inflammatory response (chemokines MCP-1 and MIP-2, cytokines TNF-α and IL-1β, adhesion molecule ICAM-1, and neutrophil and macrophage infiltration). It also markedly mitigated oxidative/nitrative stress (NOX-2, NOX-4 expression, 4-HNE and 3-NT content) and cell death. The protective effects of BCP against biochemical and histological markers of nephropathy were absent in CB2 knockout mice. Thus, BCP may be an excellent therapeutic agent to prevent cisplatin-induced nephrotoxicity through a CB2 receptor dependent pathway. Given the excellent safety profile of BCP in humans it has tremendous therapeutic potential in multitude of diseases associated with inflammation and oxidative stress. PMID:22326488

  12. β-Caryophyllene ameliorates cisplatin-induced nephrotoxicity in a cannabinoid 2 receptor-dependent manner.

    PubMed

    Horváth, Béla; Mukhopadhyay, Partha; Kechrid, Malek; Patel, Vivek; Tanchian, Galin; Wink, David A; Gertsch, Jürg; Pacher, Pál

    2012-04-15

    (E)-β-caryophyllene (BCP) is a natural sesquiterpene found in many essential oils of spice (best known for contributing to the spiciness of black pepper) and food plants with recognized anti-inflammatory properties. Recently it was shown that BCP is a natural agonist of endogenous cannabinoid 2 (CB(2)) receptors, which are expressed in immune cells and mediate anti-inflammatory effects. In this study we aimed to test the effects of BCP in a clinically relevant murine model of nephropathy (induced by the widely used antineoplastic drug cisplatin) in which the tubular injury is largely dependent on inflammation and oxidative/nitrative stress. β-caryophyllene dose-dependently ameliorated cisplatin-induced kidney dysfunction, morphological damage, and renal inflammatory response (chemokines MCP-1 and MIP-2, cytokines TNF-α and IL-1β, adhesion molecule ICAM-1, and neutrophil and macrophage infiltration). It also markedly mitigated oxidative/nitrative stress (NOX-2 and NOX-4 expression, 4-HNE and 3-NT content) and cell death. The protective effects of BCP against biochemical and histological markers of nephropathy were absent in CB(2) knockout mice. Thus, BCP may be an excellent therapeutic agent to prevent cisplatin-induced nephrotoxicity through a CB(2) receptor-dependent pathway. Given the excellent safety profile of BCP in humans it has tremendous therapeutic potential in a multitude of diseases associated with inflammation and oxidative stress.

  13. Centrally mediated antinociceptive effects of cannabinoid receptor ligands in rat models of nociception

    PubMed Central

    Hama, Aldric; Sagen, Jacqueline

    2011-01-01

    The endogenous nonapeptide hemopressin (HE) demonstrates potent block of the cannabinoid subtype-1 (CB1) receptor in vitro and robust antinociception in vivo. The current study evaluated the effects of centrally administered HE in mechanistically distinct pre-clinical rat models of pain—the hot plate test and the hind paw formalin test. The non-subtype selective CB receptor agonist WIN 55,212-2 was tested concurrently as a positive control. In the hot plate test, neither intrathecal (i.t.) HE nor WIN 55,212-2 significantly altered the latency to respond to noxious heat. By contrast, i.t. HE and WIN 55,212-2 significantly reduced pain-related behaviors in the formalin test. Possible HE functionality as a CB1 receptor antagonist at the spinal level was evaluated in the formalin test. Intrathecal pretreatment with HE did not attenuate the antinociceptive effect of i.t. WIN 55,212-2. However, pretreatment with the CB1 receptor antagonist rimonabant did; i.t. rimonabant pretreatment was not antinociceptive. Potential supraspinal antinociceptive activity of HE was also evaluated. Whereas intracerebroventricular (i.c.v.) injection of WIN 55,212-2 reduced pain-related behaviors in the formalin test, interestingly, i.c.v. HE increased behaviors. In the current study, an antinociceptive effect with the CB receptor ligand HE was obtained under the specific condition of tissue injury and not in the uninjured state. Thus, HE could be a useful analgesic peptide with a novel spinal mechanism of action. PMID:21958947

  14. Involvement of cannabinoid receptors in infrasonic noise-induced neuronal impairment.

    PubMed

    Ma, Lei; He, Hua; Liu, Xuedong; Zhang, Guangyun; Li, Li; Yan, Song; Li, Kangchu; Shi, Ming

    2015-08-01

    Excessive exposure to infrasound, a kind of low-frequency but high-intensity sound noise generated by heavy transportations and machineries, can cause vibroacoustic disease which is a progressive and systemic disease, and finally results in the dysfunction of central nervous system. Our previous studies have demonstrated that glial cell-mediated inflammation may contribute to infrasound-induced neuronal impairment, but the underlying mechanisms are not fully understood. Here, we show that cannabinoid (CB) receptors may be involved in infrasound-induced neuronal injury. After exposure to infrasound at 16 Hz and 130 dB for 1-14 days, the expression of CB receptors in rat hippocampi was gradually but significantly decreased. Their expression levels reached the minimum after 7- to 14-day exposure during which the maximum number of apoptotic cells was observed in the CA1. 2-Arachidonoylglycerol (2-AG), an endogenous agonist for CB receptors, reduced the number of infrasound-triggered apoptotic cells, which, however, could be further increased by CB receptor antagonist AM251. In animal behavior performance test, 2-AG ameliorated the infrasound-impaired learning and memory abilities of rats, whereas AM251 aggravated the infrasound-impaired learning and memory abilities of rats. Furthermore, the levels of proinflammatory cytokines tumor necrosis factor alpha and interleukin-1β in the CA1 were upregulated after infrasound exposure, which were attenuated by 2-AG but further increased by AM251. Thus, our results provide the first evidence that CB receptors may be involved in infrasound-induced neuronal impairment possibly by affecting the release of proinflammatory cytokines.

  15. Cannabidiol inhibits human glioma cell migration through a cannabinoid receptor-independent mechanism

    PubMed Central

    Vaccani, Angelo; Massi, Paola; Colombo, Arianna; Rubino, Tiziana; Parolaro, Daniela

    2005-01-01

    We evaluated the ability of cannabidiol (CBD) to impair the migration of tumor cells stimulated by conditioned medium. CBD caused concentration-dependent inhibition of the migration of U87 glioma cells, quantified in a Boyden chamber. Since these cells express both cannabinoid CB1 and CB2 receptors in the membrane, we also evaluated their engagement in the antimigratory effect of CBD. The inhibition of cell was not antagonized either by the selective cannabinoid receptor antagonists SR141716 (CB1) and SR144528 (CB2) or by pretreatment with pertussis toxin, indicating no involvement of classical cannabinoid receptors and/or receptors coupled to Gi/o proteins. These results reinforce the evidence of antitumoral properties of CBD, demonstrating its ability to limit tumor invasion, although the mechanism of its pharmacological effects remains to be clarified. PMID:15700028

  16. Receptome: Interactions between three pain-related receptors or the "Triumvirate" of cannabinoid, opioid and TRPV1 receptors.

    PubMed

    Zádor, Ferenc; Wollemann, Maria

    2015-12-01

    A growing amount of data demonstrates the interactions between cannabinoid, opioid and the transient receptor potential (TRP) vanilloid type 1 (TRPV1) receptors. These interactions can be bidirectional, inhibitory or excitatory, acute or chronic in their nature, and arise both at the molecular level (structurally and functionally) and in physiological processes, such as pain modulation or perception. The interactions of these three pain-related receptors may also reserve important and new therapeutic applications for the treatment of chronic pain or inflammation. In this review, we summarize the main findings on the interactions between the cannabinoid, opioid and the TRPV1 receptor regarding to pain modulation.

  17. Involvement of cannabinoid receptors in gut motility and visceral perception

    PubMed Central

    Hornby, Pamela J; Prouty, Stephen M

    2004-01-01

    From a historical perspective to the present day, all the evidence suggests that activation of cannabinoid receptors (CBRs) is beneficial for gut discomfort and pain, which are symptoms related to dysmotility and visceral perception. CBRs comprise G-protein coupled receptors that are predominantly in enteric and central neurones (CB1R) and immune cells (CB2R). In the last decade, evidence obtained from the use of selective agonists and inverse agonists/antagonists indicates that manipulation of CB1R can alter (1) sensory processing from the gut, (2) brain integration of brain-gut axis, (3) extrinsic control of the gut and (4) intrinsic control by the enteric nervous system. The extent to which activation of CB1R is most critical at these different levels is related to the region of the GI tract. The upper GI tract is strongly influenced by CB1R activation on central vagal pathways, whereas intestinal peristalsis can be modified by CB1R activation in the absence of extrinsic input. Actions at multiple levels make the CB1R a target for the treatment of functional bowel disorders, such as IBS. Since low-grade inflammation may act as a trigger for occurrence of IBS, CB2R modulation could be beneficial, but there is little supporting evidence for this yet. The challenge is to accomplish CBR activation while minimizing adverse effects and abuse liabilities. Potential therapeutic strategies involve increasing signaling by endocannabinoids (EC). The pathways involved in the biosynthesis, uptake and degradation of EC provide opportunities for modulation of CB1R and some recent evidence with inhibitors of EC uptake and metabolism suggest that these could be exploited for therapeutic gain. PMID:15100166

  18. Evaluation of first generation synthetic cannabinoids on binding at non-cannabinoid receptors and in a battery of in vivo assays in mice.

    PubMed

    Wiley, Jenny L; Lefever, Timothy W; Marusich, Julie A; Grabenauer, Megan; Moore, Katherine N; Huffman, John W; Thomas, Brian F

    2016-11-01

    Anecdotal reports suggest that abused synthetic cannabinoids produce cannabis-like "highs," but some of their effects may also differ from traditional cannabinoids such as Δ(9)-tetrahydrocannabinol (THC). This study examined the binding affinities of first-generation indole-derived synthetic cannabinoids at cannabinoid and noncannabinoid receptors and their effects in a functional observational battery (FOB) and drug discrimination in mice. All seven compounds, except JWH-391, had favorable affinity (≤159 nM) for both cannabinoid receptors. In contrast, binding at noncannabinoid receptors was absent or weak. In the FOB, THC and the six active compounds disrupted behaviors in CNS activation and muscle tone/equilibrium domains. Unlike THC, however, synthetic cannabinoids impaired behavior across a wider dose and domain range, producing autonomic effects and signs of CNS excitability and sensorimotor reactivity. In addition, mice acquired JWH-018 discrimination, and THC and JWH-073 produced full substitution whereas the 5-HT2B antagonist mianserin did not substitute in mice trained to discriminate JWH-018 or THC. Urinary metabolite analysis showed that the compounds were extensively metabolized, with metabolites that could contribute to their in vivo effects. Together, these results show that, while first-generation synthetic cannabinoids shared some effects that were similar to those of THC, they also possessed effects that differed from traditional cannabinoids. The high nanomolar (or absent) affinities of these compounds at receptors for most major neurotransmitters suggests that these divergent effects may be related to the greater potencies and/or efficacies at CB1 receptors; however, action(s) at noncannabinoid receptors yet to be assessed or via different signaling pathways cannot be ruled out.

  19. Co-expression of the human cannabinoid receptor coding region splice variants (hCB₁) affects the function of hCB₁ receptor complexes.

    PubMed

    Bagher, Amina M; Laprairie, Robert B; Kelly, Melanie E M; Denovan-Wright, Eileen M

    2013-12-05

    The human type 1 cannabinoid (hCB1) receptor is expressed at high levels in the central nervous system. mRNA variants of the coding region of this receptor, human cannabinoid hCB1a and hCB1b receptors, have been identified, their biological function remains unclear. The present study demonstrated that the three human cannabinoid hCB1 coding region variants are expressed in the human and monkey (Macaca fascicularis) brain. Western blot analyses of homogenates from different regions of the monkey brain demonstrated that proteins with the expected molecular weights of the cannabinoid CB1, CB1a and CB1b receptors were co-expressed throughout the brain. Given the co-localization of these receptors, we hypothesized that physical interactions between the three splice variants may affect cannabinoid pharmacology. The human cannabinoid hCB1, hCB1a, and hCB1b receptors formed homodimers and heterodimers, as determined by BRET in transiently transfected HEK 293A cells. We found that the co-expression of the human cannabinoid hCB1 and each of the splice variants increased cell surface expression of the human cannabinoid hCB1 receptor and increased Gi/o-dependent ERK phosphorylation in response to cannabinoid agonists. Therefore, the human cannabinoid hCB1 coding region splice variants play an important physiological role in the activity of the endocannabinoid system.

  20. Synthetic cannabinoids: In silico prediction of the cannabinoid receptor 1 affinity by a quantitative structure-activity relationship model.

    PubMed

    Paulke, Alexander; Proschak, Ewgenij; Sommer, Kai; Achenbach, Janosch; Wunder, Cora; Toennes, Stefan W

    2016-03-14

    The number of new synthetic psychoactive compounds increase steadily. Among the group of these psychoactive compounds, the synthetic cannabinoids (SCBs) are most popular and serve as a substitute of herbal cannabis. More than 600 of these substances already exist. For some SCBs the in vitro cannabinoid receptor 1 (CB1) affinity is known, but for the majority it is unknown. A quantitative structure-activity relationship (QSAR) model was developed, which allows the determination of the SCBs affinity to CB1 (expressed as binding constant (Ki)) without reference substances. The chemically advance template search descriptor was used for vector representation of the compound structures. The similarity between two molecules was calculated using the Feature-Pair Distribution Similarity. The Ki values were calculated using the Inverse Distance Weighting method. The prediction model was validated using a cross validation procedure. The predicted Ki values of some new SCBs were in a range between 20 (considerably higher affinity to CB1 than THC) to 468 (considerably lower affinity to CB1 than THC). The present QSAR model can serve as a simple, fast and cheap tool to get a first hint of the biological activity of new synthetic cannabinoids or of other new psychoactive compounds.

  1. The effects of delta9-tetrahydrocannabinol physical dependence on brain cannabinoid receptors.

    PubMed

    Breivogel, Christopher S; Scates, Susan M; Beletskaya, Irina O; Lowery, Olivia B; Aceto, Mario D; Martin, Billy R

    2003-01-17

    The effects of chronic Delta(9)-tetrahydrocannabinol on cannabinoid receptor levels and receptor-G-protein coupling were investigated. Male Sprague-Dawley rats were infused continuously with low or high dose regimens of Delta(9)-tetrahydrocannabinol or vehicle for 4 days. Following treatment, rats were sacrificed for cannabinoid CB(1) receptor binding analysis or challenged with the cannabinoid CB(1) receptor antagonist, N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide HCl (SR141716A). The rats receiving Delta(9)-tetrahydrocannabinol exhibited antagonist-precipitated withdrawal signs. Each brain region (cerebellum, cortex, hippocampus and basal ganglia) from high-dose rats showed 30-70% decreases in [3H] (-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxyphenyl)cyclohexanol (WIN55212-2) B(max) values, indicating receptor down-regulation. Most regions showed decreased WIN55212-2-stimulated [35S]guanosine-5'-O-3-thiotriphosphate (GTPgammaS) binding, indicating desensitization of cannabinoid CB(1) receptors. Additional receptor binding assays in cerebellar membranes showed a significantly greater decrease in agonist than in antagonist B(max) values, indicating a lower fraction of coupled receptors after treatment. Concentration-effect analysis of five agonists revealed that the treatment resulted in greater decreases in the efficacy of low-efficacy agonists.

  2. The cannabinoid CB1 receptor antagonists rimonabant (SR141716) and AM251 directly potentiate GABAA receptors

    PubMed Central

    Baur, R; Gertsch, J; Sigel, E

    2012-01-01

    BACKGROUND AND PURPOSE Rimonabant (SR141716) and the structurally related AM251 are widely used in pharmacological experiments as selective cannabinoid receptor CB1 antagonists / inverse agonists. Concentrations of 0.5–10 µM are usually applied in in vitro experiments. We intended to show that these drugs did not act at GABAA receptors but found a significant positive allosteric modulation instead. EXPERIMENTAL APPROACH Recombinant GABAA receptors were expressed in Xenopus oocytes. Receptors were exposed to AM251 or rimonabant in the absence and presence of GABA. Standard electrophysiological techniques were used to monitor the elicited ionic currents. KEY RESULTS AM251 dose-dependently potentiated responses to 0.5 µM GABA at the recombinant α1β2γ2 GABAA receptor with an EC50 below 1 µM and a maximal potentiation of about eightfold. The Hill coefficient indicated that more than one binding site for AM251 was located in this receptor. Rimonabant had a lower affinity, but a fourfold higher efficacy. AM251 potentiated also currents mediated by α1β2, αxβ2γ2 (x = 2,3,5,6), α1β3γ2 and α4β2δ GABAA receptors, but not those mediated by α1β1γ2. Interestingly, the CB1 receptor antagonists LY320135 and O-2050 did not significantly affect α1β2γ2 GABAA receptor-mediated currents at concentrations of 1 µM. CONCLUSIONS AND IMPLICATIONS This study identified rimonabant and AM251 as positive allosteric modulators of GABAA receptors. Thus, potential GABAergic effects of commonly used concentrations of these compounds should be considered in in vitro experiments, especially at extrasynaptic sites where GABA concentrations are low. LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7 PMID:21470203

  3. THE NEURONAL DISTRIBUTION OF CANNABINOID RECEPTOR TYPE 1 IN THE TRIGEMINAL GANGLION OF THE RAT

    PubMed Central

    PRICE, T. J.; HELESIC, G.; PARGHI, D.; HARGREAVES, K. M.; FLORES, C. M.

    2007-01-01

    Cannabinoid compounds have been shown to produce antinociception and antihyperalgesia by acting upon cannabinoid receptors located in both the CNS and the periphery. A potential mechanism by which cannabinoids could inhibit nociception in the periphery is the activation of cannabinoid receptors located on one or more classes of primary nociceptive neurons. To address this hypothesis, we evaluated the neuronal distribution of cannabinoid receptor type 1 (CB1) in the trigeminal ganglion (TG) of the adult rat through combined in situ hybridization (ISH) and immunohistochemistry (IHC). CB1 receptor mRNA was localized mainly to medium and large diameter neurons of the maxillary and mandibular branches of the TG. Consistent with this distribution, in a de facto nociceptive sensory neuron population that exhibited vanilloid receptor type 1 immunoreactivity, colocalization with CB1 mRNA was also sparse (<5%). Furthermore, very few neurons (approximately 5%) in the peptidergic (defined as calcitonin gene-related peptide- or substance P-immunoreactive) or the isolectin B4-binding sensory neuron populations contained CB1 mRNA. In contrast, and consistent with the neuron-size distribution for CB1, nearly 75% of CB1-positive neurons exhibited N52-immunoreactivity, a marker of myelinated axons. These results indicate that in the rat TG, CB1 receptors are expressed predominantly in neurons that are not thought to subserve nociceptive neurotransmission in the noninjured animal. Taken together with the absence of an above background in situ signal for CB2 mRNA in TG neurons, these findings suggest that the peripherally mediated antinociceptive effects of cannabinoids may involve either as yet unidentified receptors or interaction with afferent neuron populations that normally subserve non-nociceptive functions. PMID:12849749

  4. β-arrestins: regulatory role and therapeutic potential in opioid and cannabinoid receptor-mediated analgesia.

    PubMed

    Raehal, Kirsten M; Bohn, Laura M

    2014-01-01

    Pain is a complex disorder with neurochemical and psychological components contributing to the severity, the persistence, and the difficulty in adequately treating the condition. Opioid and cannabinoids are two classes of analgesics that have been used to treat pain for centuries and are arguably the oldest of "pharmacological" interventions used by man. Unfortunately, they also produce several adverse side effects that can complicate pain management. Opioids and cannabinoids act at G protein-coupled receptors (GPCRs), and much of their effects are mediated by the mu-opioid receptor (MOR) and cannabinoid CB1 receptor (CB1R), respectively. These receptors couple to intracellular second messengers and regulatory proteins to impart their biological effects. In this chapter, we review the role of the intracellular regulatory proteins, β-arrestins, in modulating MOR and CB1R and how they influence the analgesic and side-effect profiles of opioid and cannabinoid drugs in vivo. This review of the literature suggests that the development of opioid and cannabinoid agonists that bias MOR and CB1R toward G protein signaling cascades and away from β-arrestin interactions may provide a novel mechanism by which to produce analgesia with less severe adverse effects.

  5. β-Arrestins: Regulatory Role and Therapeutic Potential in Opioid and Cannabinoid Receptor-Mediated Analgesia

    PubMed Central

    Bohn, Laura M.

    2016-01-01

    Pain is a complex disorder with neurochemical and psychological components contributing to the severity, the persistence, and the difficulty in adequately treating the condition. Opioid and cannabinoids are two classes of analgesics that have been used to treat pain for centuries and are arguably the oldest of “pharmacological” interventions used by man. Unfortunately, they also produce several adverse side effects that can complicate pain management. Opioids and cannabinoids act at G protein-coupled receptors (GPCRs), and much of their effects are mediated by the mu-opioid receptor (MOR) and cannabinoid CB1 receptor (CB1R), respectively. These receptors couple to intracellular second messengers and regulatory proteins to impart their biological effects. In this chapter, we review the role of the intracellular regulatory proteins, β-arrestins, in modulating MOR and CB1R and how they influence the analgesic and side-effect profiles of opioid and cannabinoid drugs in vivo. This review of the literature suggests that the development of opioid and cannabinoid agonists that bias MOR and CB1R toward G protein signaling cascades and away from β-arrestin interactions may provide a novel mechanism by which to produce analgesia with less severe adverse effects. PMID:24292843

  6. Nonpsychotropic cannabinoids, abnormal cannabidiol and canabigerol-dimethyl heptyl, act at novel cannabinoid receptors to reduce intraocular pressure.

    PubMed

    Szczesniak, Anna-Maria; Maor, Yehoshua; Robertson, Harold; Hung, Orlando; Kelly, Melanie E M

    2011-10-01

    The objective of our study was to examine the pharmacology of the intraocular pressure (IOP)-lowering actions of the behaviorally inactive cannabinoids, abnormal cannabidiol (abn-CBD), and a cannabigerol analog, cannabigerol-dimethyl heptyl (CBG-DMH), in comparison to that of the nonselective cannabinoid 1 receptor (CB(1)R) and CB(2)R agonist, WIN55,212-2, in Brown Norway rats. The IOP was measured noninvasively using a hand-held tonometer in nonanesthetized animals. The IOP measurements were taken every 15 min for a period of 2 h after drug administration. All drugs were administered via intraperitoneal (i.p.) injections, and abn-CBD and CBG-DMH were also given topically. Both abn-CBD and CBG-DMH reduced IOP when administrated i.p. at doses of ≥2.5 mg/kg or topically at concentrations of 1%-2%. The IOP-lowering effects of abn-CBD and CBG-DMH were reduced by i.p. administration of O-1918 (2.5 mg/kg), a selective antagonist of the abn-CBD-sensitive cannabinoid-related receptor (CBx), but were unaffected by the CB(1)R antagonist, AM251 (2.5 mg/kg), or the CB(2)R antagonist, AM630 (2.5 mg/kg). In contrast, the IOP-lowering action of WIN55,212-2 was completely blocked by the CB(1)R-selective antagonist, AM251, and was unaffected by the CBx receptor antagonist, O-1918. However, similar to the nonpsychotropic cannabinoids, the ocular hypotensive actions of WIN55,212-2 were also insensitive to block by the CB(2)R antagonist, AM630. Consistent with this, the selective CB(2)R agonist, HU-308 (2 mg/kg) failed to reduce IOP in Brown Norway rats. Concurrent application of a dose of WIN55,212-2 that was subthreshold to reduce IOP (0.25 mg/kg), together with a topical dose of either abn-CBD (0.5%) or CBG-DMH (0.25%), respectively, potentiated the ocular hypotensive effect of either compound applied alone. This study demonstrates that the atypical cannabinoid, abn-CBD, and the cannabigerol analog, CBG-DMH, decrease IOP in the normotensive Brown Norway rat eye independent of CB

  7. Cannabinoid Receptors in Regulating the GI Tract: Experimental Evidence and Therapeutic Relevance.

    PubMed

    Taschler, Ulrike; Hasenoehrl, Carina; Storr, Martin; Schicho, Rudolf

    2017-02-05

    Cannabinoid receptors are fundamentally involved in all aspects of intestinal physiology, such as motility, secretion, and epithelial barrier function. They are part of a broader entity, the so-called endocannabinoid system which also includes their endocannabinoid ligands and the ligands' synthesizing/degrading enzymes. The system has a strong impact on the pathophysiology of the gastrointestinal tract and is believed to maintain homeostasis in the gut by controlling hypercontractility and by promoting regeneration after injury. For instance, genetic knockout of cannabinoid receptor 1 leads to inflammation and cancer of the intestines. Derivatives of Δ(9)-tetrahydrocannabinol, such as nabilone and dronabinol, activate cannabinoid receptors and have been introduced into the clinic to treat chemotherapy-induced emesis and loss of appetite; however, they may cause many psychotropic side effects. New drugs that interfere with endocannabinoid degradation to raise endocannabinoid levels circumvent this obstacle and could be used in the future to treat emesis, intestinal inflammation, and functional disorders associated with visceral hyperalgesia.

  8. Cannabinoid and heroin activation of mesolimbic dopamine transmission by a common mu1 opioid receptor mechanism.

    PubMed

    Tanda, G; Pontieri, F E; Di Chiara, G

    1997-06-27

    The effects of the active ingredient of Cannabis, Delta9-tetrahydrocannabinol (Delta9-THC), and of the highly addictive drug heroin on in vivo dopamine transmission in the nucleus accumbens were compared in Sprague-Dawley rats by brain microdialysis. Delta9-THC and heroin increased extracellular dopamine concentrations selectively in the shell of the nucleus accumbens; these effects were mimicked by the synthetic cannabinoid agonist WIN55212-2. SR141716A, an antagonist of central cannabinoid receptors, prevented the effects of Delta9-THC but not those of heroin. Naloxone, a generic opioid antagonist, administered systemically, or naloxonazine, an antagonist of micro1 opioid receptors, infused into the ventral tegmentum, prevented the action of cannabinoids and heroin on dopamine transmission. Thus, Delta9-THC and heroin exert similar effects on mesolimbic dopamine transmission through a common mu1 opioid receptor mechanism located in the ventral mesencephalic tegmentum.

  9. Selective Cannabinoid Receptor-1 Agonists Regulate Mast Cell Activation in an Oxazolone-Induced Atopic Dermatitis Model

    PubMed Central

    Nam, Gaewon; Jeong, Se Kyoo; Park, Bu Man; Lee, Sin Hee; Kim, Hyun Jong; Hong, Seung-Phil; Kim, Beomjoon

    2016-01-01

    Background Many inflammatory mediators, including various cytokines (e.g. interleukins and tumor necrosis factor [TNF]), inflammatory proteases, and histamine are released following mast cell activation. However, the endogenous modulators for mast cell activation and the underlying mechanism have yet to be elucidated. Endogenous cannabinoids such as palmitoylethanolamide (PEA) and N-arachidonoylethanolamine (anandamide or AEA), were found in peripheral tissues and have been proposed to possess autacoid activity, implying that cannabinoids may downregulate mast cell activation and local inflammation. Objective In order to investigate the effect of cannabinoid receptor-1 (CB1R) agonists on mast cell activation, AEA-derived compounds were newly synthesized and evaluated for their effect on mast cell activation. Methods The effects of selected compounds on FcεRI-induced histamine and β-hexosaminidase release were evaluated in a rat basophilic leukemia cell line (RBL-2H3). To further investigate the inhibitory effects of CB1R agonist in vivo, an oxazolone-induced atopic dermatitis mouse model was exploited. Results We found that CB1R inhibited the release of inflammatory mediators without causing cytotoxicity in RBL-2H3 cells and that CB1R agonists markedly and dose-dependently suppressed mast cell proliferation indicating that CB1R plays an important role in modulating antigen-dependent immunoglobulin E (IgE)-mediated mast cell activation. We also found that topical application of CB1R agonists suppressed the recruitment of mast cells into the skin and reduced the level of blood histamine. Conclusion Our results indicate that CB1R agonists down-regulate mast cell activation and may be used for relieving inflammatory symptoms mediated by mast cell activation, such as atopic dermatitis, psoriasis, and contact dermatitis. PMID:26848215

  10. Cannabinoids and the gastrointestinal tract

    PubMed Central

    PERTWEE, R

    2001-01-01

    found to induce "withdrawal" contractions in cannabinoid tolerant guinea pig ileal MPLM. Further research is required to investigate the role both of endogenous cannabinoid receptor agonists and of non-CB1 cannabinoid receptors in the gastrointestinal tract. The extent to which the effects on gastrointestinal function of cannabinoid receptor agonists or antagonists/inverse agonists can be exploited therapeutically has yet to be investigated as has the extent to which these drugs can provoke unwanted effects in the gastrointestinal tract when used for other therapeutic purposes.

 PMID:11358910

  11. Cannabinoid receptor agonists reduce the short-term mitochondrial dysfunction and oxidative stress linked to excitotoxicity in the rat brain.

    PubMed

    Rangel-López, E; Colín-González, A L; Paz-Loyola, A L; Pinzón, E; Torres, I; Serratos, I N; Castellanos, P; Wajner, M; Souza, D O; Santamaría, A

    2015-01-29

    The endocannabinoid system (ECS) is involved in a considerable number of physiological processes in the Central Nervous System. Recently, a modulatory role of cannabinoid receptors (CBr) and CBr agonists on the reduction of the N-methyl-d-aspartate receptor (NMDAr) activation has been demonstrated. Quinolinic acid (QUIN), an endogenous analog of glutamate and excitotoxic metabolite produced in the kynurenine pathway (KP), selectively activates NMDAr and has been shown to participate in different neurodegenerative disorders. Since the early pattern of toxicity exerted by this metabolite is relevant to explain the extent of damage that it can produce in the brain, in this work we investigated the effects of the synthetic CBr agonist WIN 55,212-2 (WIN) and other agonists (anandamide or AEA, and CP 55,940 or CP) on early markers of QUIN-induced toxicity in rat striatal cultured cells and rat brain synaptosomes. WIN, AEA and CP exerted protective effects on the QUIN-induced loss of cell viability. WIN also preserved the immunofluorescent signals for neurons and CBr labeling that were decreased by QUIN. The QUIN-induced early mitochondrial dysfunction, lipid peroxidation and reactive oxygen species (ROS) formation were also partially or completely prevented by WIN pretreatment, but not when this CBr agonist was added simultaneously with QUIN to brain synaptosomes. These findings support a neuroprotective and modulatory role of cannabinoids in the early toxic events elicited by agents inducing excitotoxic processes.

  12. Anandamide inhibits nuclear factor-kappaB activation through a cannabinoid receptor-independent pathway.

    PubMed

    Sancho, Rocío; Calzado, Marco A; Di Marzo, Vincenzo; Appendino, Giovanni; Muñoz, Eduardo

    2003-02-01

    Anandamide (arachidonoylethanolamine, AEA), an endogenous agonist for both the cannabinoid CB(1) receptor and the vanilloid VR1 receptor, elicits neurobehavioral, anti-inflammatory, immunomodulatory, and proapoptotic effects. Because of the central role of nuclear factor-kappaB (NF-kappaB) in the inflammatory process and the immune response, we postulated that AEA might owe some of its effects to the suppression of NF-kappaB. This study shows that AEA inhibits tumor necrosis factor-alpha (TNFalpha)-induced NF-kappaB activation by direct inhibition of the IkappaB kinase (IKK)beta and, to a lesser extent, the IKKalpha subunits of kappaB inhibitor (IkappaB) kinase complex, and that IKKs inhibition by AEA correlates with inhibition of IkappaBalpha degradation, NF-kappaB binding to DNA, and NF-kappaB-dependent transcription in TNFalpha-stimulated cells. AEA also prevents NF-kappaB-dependent reporter gene expression induced by mitogen-activated protein kinase kinase kinase and NF-kappaB-inducing kinase. The NF-kappaB inhibitory activity of AEA was independent of CB(1) and CB(2) activation in TNFalpha-stimulated 5.1 and A549 cell lines, which do not express vanilloid receptor 1, and was not mediated by hydrolytic products formed through the activity of the enzyme fatty acid amide hydrolase. Chemical modification markedly affected AEA inhibitory activity on NF-kappaB, suggesting rather narrow structure-activity relationships and the specific interaction with a molecular target. Substitution of the alkyl moiety with less saturated fatty acids generally reduced or abolished activity. However, replacement of the ethanolamine "head" with a vanillyl group led to potent inhibition of TNFalpha-induced NF-kappaB-dependent transcription. These findings provide new mechanistic insights into the anti-inflammatory and proapoptotic activities of AEA, and should foster the synthesis of improved analogs amenable to pharmaceutical development as anti-inflammatory agents.

  13. Role of cannabinoid CB1 receptors on macronutrient selection and satiety in rats.

    PubMed

    Escartín-Pérez, Rodrigo Erick; Cendejas-Trejo, Nancy Mónica; Cruz-Martínez, Ana María; González-Hernández, Brenda; Mancilla-Díaz, Juan Manuel; Florán-Garduño, Benjamín

    2009-03-23

    It has been shown that endogenous and exogenous cannabinoids substantially increase feeding. Despite evidence for a role of endocannabinoids in mediating food ingestion, the mechanisms by which CB1 receptor agonists and antagonists have an effect on motivational processes (hunger, satiety) as well as on specific food preference are not entirely understood. The purpose of this study was to investigate the effects of systemic injection of the CB1 receptor agonist, ACEA, on protein, carbohydrates and fat intake as well as on the behavioural satiety sequence (BSS) in pre-satiated rats. Following a 120-min access to a three pure nutrient diet (protein, carbohydrates and fat) at dark onset, male Wistar rats were injected intraperitoneally with ACEA (0.1, 0.25, 0.5 and 1.0 mg/kg). Immediately after the injection, animals were placed into separate experimental cages with free access to food and a single 60-min period was video recorded to evaluate the BSS; protein, carbohydrates and fat intake (g) was measured at the same period of time. Intake of carbohydrates was significantly increased and this effect was prevented by the pre-treatment with AM 251. Analysis of BSS showed that administration of 0.5 mg/kg of ACEA reversed the satiation induced by food ingestion by increasing the time spent eating and decreasing the time resting without altering the overall activity. The present results suggest that the stimulation of food intake induced by activation of CB1 receptors involves a specific dietary component and behavioural selective mechanisms (stimulating hunger and inhibiting satiety).

  14. Identification of N‐arachidonoyl dopamine as a highly biased ligand at cannabinoid CB1 receptors

    PubMed Central

    Redmond, William J.; Cawston, Erin E.; Grimsey, Natasha L.; Stuart, Jordyn; Edington, Amelia R.; Glass, Michelle

    2015-01-01

    Background and Purpose N‐arachidonyl dopamine (NADA) has been identified as a putative endocannabinoid, but there is little information about which signalling pathways it activates. The purpose of this study was to identify the signalling pathways activated by NADA in vitro. Experimental Approach Human or rat cannabinoid CB1 receptors were expressed in AtT20, CHO or HEK 293 cells. NADA displacement of radiolabelled cannabinoids, and CB1 receptor mediated activation of K channels or ERK phosphorylation, release of intracellular calcium ([Ca]i) and modulation of adenylyl cyclase were measured in addition to NADA effects on CB1 receptor trafficking. Key Results At concentrations up to 30 μM, NADA failed to activate any signalling pathways via CB1 receptors, with the exception of mobilization of [Ca]i. The elevations of [Ca]i were insensitive to pertussis toxin, and reduced or abolished by blockers of Gq/11‐dependent processes including U73122, thapsigargin and a peptide antagonist of Gq/11 activation. Prolonged NADA incubation produced modest loss of cell surface CB1 receptors. The prototypical cannabinoid agonist CP55940 signalled as expected in all assays. Conclusions and Implications NADA is an ineffective agonist at most canonical cannabinoid receptor signalling pathways, but did promote mobilization of [Ca]i via Gq‐dependent processes and some CB1 receptor trafficking. This signalling profile is distinct from that of any known cannabinoid, and suggests that NADA may have a unique spectrum of effects in vivo. Our results also indicate that it may be possible to identify highly biased CB1 receptor ligands displaying a subset of the pharmacological or therapeutic effects usually attributed to CB1 ligands. PMID:26398720

  15. Cannabinoid Receptors Couple to NMDA Receptors to Reduce the Production of NO and the Mobilization of Zinc Induced by Glutamate

    PubMed Central

    Sánchez-Blázquez, Pilar; Rodríguez-Muñoz, María; Vicente-Sánchez, Ana

    2013-01-01

    Abstract Aims: Overactivation of glutamate N-methyl-D-aspartate receptor (NMDAR) increases the cytosolic concentrations of calcium and zinc, which significantly contributes to neural death. Since cannabinoids prevent the NMDAR-mediated increase in cytosolic calcium, we investigated whether they also control the rise of potentially toxic free zinc ions, as well as the processes implicated in this phenomenon. Results: The cannabinoid receptors type 1 (CNR1) and NMDARs are cross-regulated in different regions of the nervous system. Cannabinoids abrogated the stimulation of the nitric oxide-zinc pathway by NMDAR, an effect that required the histidine triad nucleotide-binding protein 1 (HINT1). Conversely, NMDAR antagonism reduced the analgesia promoted by the CNR1 agonist WIN55,212-2 and impaired its capacity to internalize CNR1s. At the cell surface, CNR1s co-immunoprecipitated with the NR1 subunits of NMDARs, an association that diminished after the administration of NMDA in vivo or as a consequence of neuropathic overactivation of NMDARs, both situations in which cannabinoids do not control NMDAR activity. Under these circumstances, inhibition of protein kinase A (PKA) restored the association between CNR1s and NR1 subunits, and cannabinoids regained control over NMDAR activity. Notably, CNR1 and NR1 associated poorly in HINT1−/− mice, in which there was little cross-regulation between these receptors. Innovation: The CNR1 can regulate NMDAR function when the receptor is coupled to HINT1. Thus, internalization of CNR1s drives the co-internalization of the NR1 subunits, neutralizing the overactivation of NMDARs. Conclusion: Cannabinoids require the HINT1 protein to counteract the toxic effects of NMDAR-mediated NO production and zinc release. This study situates the HINT1 protein at the forefront of cannabinoid protection against NMDAR-mediated brain damage. Antioxid. Redox Signal. 19, 1766–1782. PMID:23600761

  16. Muscarinic M1 receptor and cannabinoid CB1 receptor do not modulate paraoxon-induced seizures

    PubMed Central

    Kow, Rebecca L; Cheng, Eugene M; Jiang, Kelly; Le, Joshua H; Stella, Nephi; Nathanson, Neil M

    2015-01-01

    One of the major signs of severe organophosphate poisoning is seizures. Previous studies have shown that both muscarinic agonist- and organophosphate-induced seizures require activation of muscarinic acetylcholine receptors in the central nervous system. Seizures induced by the muscarinic agonist pilocarpine require the M1 receptor and are modulated by cannabinoid CB1 receptors. In this study, we determined whether M1 and CB1 receptors also regulated seizures induced by the organophosphate paraoxon. We found no differences in seizures induced by paraoxon in wild-type (WT) and M1 knockout (KO) mice, indicating that in contrast to pilocarpine seizures, M1 receptors are not required for paraoxon seizures. Furthermore, we found that pilocarpine administration resulted in seizure-independent activation of ERK in the hippocampus in a M1 receptor-dependent manner, while paraoxon did not induce seizure-independent activation of ERK in the mouse hippocampus. This shows that pilocarpine and paraoxon activated M1 receptors in the hippocampus to different extents. There were no differences in seizures induced by paraoxon in WT and CB1 KO mice, and neither CB1 agonist nor antagonist administration had significant effects on paraoxon seizures, indicating that, in contrast to pilocarpine seizures, paraoxon seizures are not modulated by CB1 receptors. These results demonstrate that there are fundamental molecular differences in the regulation of seizures induced by pilocarpine and paraoxon. PMID:25692018

  17. Cannabinoid-induced stimulation of motor activity in planaria through an opioid receptor-mediated mechanism.

    PubMed

    Buttarelli, Francesca R; Pontieri, Francesco E; Margotta, Vito; Palladini, Guido

    2002-01-01

    Planaria, the most primitive example of centralization and cephalization of the nervous system along phylogeny, shows specific stereotyped behavioral patterns following exposure to drugs acting on neural transmission. In this study, the authors investigated the effects of exposure to the synthetic cannabinoid receptor agonist WTN55212.2 on motor activity in planaria. WTN55212.2 produced dose-dependent stimulation of motor behavior. High doses of the drug caused stereotyped activities identical to those seen previously with opioid agonists. These effects were antagonized by coexposure to cannabinoid or opioid receptor antagonists. The results indicate that functional interactions between cannabinoid and opioid systems are highly conserved along phylogeny, at least at the behavioral level.

  18. What We Know and Don’t Know About the Cannabinoid Receptor 2 (CB2)

    PubMed Central

    Malfitano, Anna Maria; Basu, Sreemanti; Maresz, Katarzyna; Bifulco, Maurizio; Dittel, Bonnie N.

    2015-01-01

    It well appreciated that the endocannabinoid system can regulate immune responses via the cannabinoid receptor 2 (CB2), which is primarily expressed by cells of the hematopoietic system. The endocannabinoid system is composed of receptors, ligands and enzymes controlling the synthesis and degradation of endocannabinoids. Along with endocannabinoids, both plant-derived and synthetic cannabinoids have been shown to bind to and signal through CB2 via G proteins leading to both inhibitory and stimulatory signals depending on the biological process. Because no cannabinoid ligand has been identified that only binds to CB2, the generation of mice deficient in CB2 has greatly expanded our knowledge of how CB2 contributes to immune cell development and function in health and disease. In regards to humans, genetic studies have associated CB2 with a variety of human diseases. Here, we review the endocannabinoid system with an emphasis on CB2 and its role in the immune system. PMID:24877594

  19. (+)-Cannabidiol analogues which bind cannabinoid receptors but exert peripheral activity only.

    PubMed

    Fride, Ester; Feigin, Cfir; Ponde, Datta E; Breuer, Aviva; Hanus, Lumír; Arshavsky, Nina; Mechoulam, Raphael

    2004-12-15

    Delta9-Tetrahydrocannabinol (Delta9-THC) and (-)-cannabidiol are major constituents of the Cannabis sativa plant with different pharmacological profiles: (-)-Delta9-tetrahydrocannabinol, but not (-)-cannabidiol, activates cannabinoid CB1 and CB2 receptors and induces psychoactive and peripheral effects. We have tested a series of (+)-cannabidiol derivatives, namely, (+)-cannabidiol-DMH (DMH-1,1-dimethylheptyl-), (+)-7-OH-cannabidiol-DMH, (+)-7-OH- cannabidiol, (+)-7-COOH- cannabidiol and (+)-7-COOH-cannabidiol-DMH, for central and peripheral (intestinal, antiinflammatory and peripheral pain) effects in mice. Although all (+)-cannabidiols bind to cannabinoid CB1 and CB2 receptors, only (+)-7-OH-cannabidiol-DMH was centrally active, while all (+)-cannabidiol analogues completely arrested defecation. The effects of (+)-cannabidiol-DMH and (+)-7-OH-cannabidiol-DMH were partially antagonized by the cannabinoid CB1 receptor antagonist N-(piperidiny-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (SR141716), but not by the cannabinoid CB2 receptor antagonist N-[-(1S)-endo-1,3,3-trimethil bicyclo [2.2.1] heptan-2-yl-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528), and had no effect on CB1(-/-) receptor knockout mice. (+)-Cannabidiol-DMH inhibited the peripheral pain response and arachidonic-acid-induced inflammation of the ear. We conclude that centrally inactive (+)-cannabidiol analogues should be further developed as antidiarrheal, antiinflammatory and analgesic drugs for gastrointestinal and other peripheral conditions.

  20. Cannabinoid receptor type 1- and 2-mediated increase in cyclic AMP inhibits T cell receptor-triggered signaling.

    PubMed

    Börner, Christine; Smida, Michal; Höllt, Volker; Schraven, Burkhart; Kraus, Jürgen

    2009-12-18

    The aim of this study was to characterize inhibitory mechanisms on T cell receptor signaling mediated by the cannabinoid receptors CB1 and CB2. Both receptors are coupled to G(i/o) proteins, which are associated with inhibition of cyclic AMP formation. In human primary and Jurkat T lymphocytes, activation of CB1 by R(+)-methanandamide, CB2 by JWH015, and both by Delta9-tetrahydrocannabinol induced a short decrease in cyclic AMP lasting less than 1 h. However, this decrease was followed by a massive (up to 10-fold) and sustained (at least up to 48 h) increase in cyclic AMP. Mediated by the cyclic AMP-activated protein kinase A and C-terminal Src kinase, the cannabinoids induced a stable phosphorylation of the inhibitory Tyr-505 of the leukocyte-specific protein tyrosine kinase (Lck). By thus arresting Lck in its inhibited form, the cannabinoids prevented the dephosphorylation of Lck at Tyr-505 in response to T cell receptor activation, which is necessary for the subsequent initiation of T cell receptor signaling. In this way the cannabinoids inhibited the T cell receptor-triggered signaling, i.e. the activation of the zeta-chain-associated protein kinase of 70 kDa, the linker for activation of T cells, MAPK, the induction of interleukin-2, and T cell proliferation. All of the effects of the cannabinoids were blocked by the CB1 and CB2 antagonists AM281 and AM630. These findings help to better understand the immunosuppressive effects of cannabinoids and explain the beneficial effects of these drugs in the treatment of T cell-mediated autoimmune disorders like multiple sclerosis.

  1. Enkephalin levels and the number of neuropeptide Y-containing interneurons in the hippocampus are decreased in female cannabinoid-receptor 1 knock-out mice.

    PubMed

    Rogers, Sophie A; Kempen, Tracey A Van; Pickel, Virginia M; Milner, Teresa A

    2016-05-04

    Drug addiction requires learning and memory processes that are facilitated by activation of cannabinoid-1 (CB1) and opioid receptors in the hippocampus. This involves activity-dependent synaptic plasticity that is partially regulated by endogenous opioid (enkephalin and dynorphin) and non-opioid peptides, specifically cholecystokinin, parvalbumin and neuropeptide Y, the neuropeptides present in inhibitory interneurons that co-express CB1 or selective opioid receptors. We tested the hypothesis that CB1 receptor expression is a determinant of the availability of one or more of these peptide modulators in the hippocampus. This was achieved by quantitatively analyzing the immunoperoxidase labeling for each of these neuropeptide in the dorsal hippocampus of female wild-type (CB1+/+) and cannabinoid receptor 1 knockout (CB1-/-) C57/BL6 mice. The levels of Leu(5)-enkephalin-immunoreactivity were significantly reduced in the hilus of the dentate gyrus and in stratum lucidum of CA3 in CB1-/- mice. Moreover, the numbers of neuropeptide Y-immunoreactive interneurons in the dentate hilus were significantly lower in the CB1-/- compared to wild-type mice. However, CB1+/+ and CB1-/- mice did not significantly differ in expression levels of either dynorphin or cholecystokinin, and showed no differences in numbers of parvalbumin-containing interneurons. These findings suggest that the cannabinoid and opioid systems have a nuanced, regulatory relationship that could affect the balance of excitation and inhibition in the hippocampus and thus processes such as learning that rely on this balance.

  2. Cannabinoid Receptor Activation Reverses Kainate-Induced Synchronized Population Burst Firing in Rat Hippocampus

    PubMed Central

    Mason, Rob; Cheer, Joseph F.

    2009-01-01

    Cannabinoids have been shown to possess anticonvulsant properties in whole animal models of epilepsy. The present investigation sought to examine the effects of cannabinoid receptor activation on kainic acid (KA)-induced epileptiform neuronal excitability. Under urethane anesthesia, acute KA treatment (10 mg kg−1, i.p.) entrained the spiking mode of simultaneously recorded neurons from random firing to synchronous bursting (% change in burst rate). Injection of the high-affinity cannabinoid agonist (-)-11-hydroxy-8-tetrahydrocannabinol-dimethyl-heptyl (HU210, 100 μg kg−1, i.p.) following KA markedly reduced the burst frequency (% decrease in burst frequency) and reversed synchronized firing patterns back to baseline levels. Pre-treatment with the central cannabinoid receptor (CB1) antagonist N-piperidino-5-(4-clorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-3-pyrazole-carboxamide (rimonabant, SR141716A 3 mg kg−1, i.p.) completely prevented the actions of HU210. The present results indicate that cannabinoids exert their antiepileptic effects by impeding pathological synchronization of neuronal networks in the hippocampus. PMID:19562087

  3. Cannabinoid receptor activation differentially modulates ion channels in photoreceptors of the tiger salamander.

    PubMed

    Straiker, Alex; Sullivan, Jane M

    2003-05-01

    Cannabinoid CB1 receptors have been detected in retinas of numerous species, with prominent labeling in photoreceptor terminals of the chick and monkey. CB1 labeling is well-conserved across species, suggesting that CB1 receptors might also be present in photoreceptors of the tiger salamander. Synaptic transmission in vertebrate photoreceptors is mediated by L-type calcium currents-currents that are modulated by CB1 receptors in bipolar cells of the tiger salamander. Presence of CB1 receptors in photoreceptor terminals would therefore be consistent with presynaptic modulation of synaptic transmission, a role seen for cannabinoids in other parts of the brain. Here we report immunohistochemical and electrophysiological evidence for the presence of functional CB1 receptors in rod and cone photoreceptors of the tiger salamander. The cannabinoid receptor agonist WIN 55212-2 enhances calcium currents of rod photoreceptors by 39% but decreases calcium currents of large single cones by 50%. In addition, WIN 55212-2 suppresses potassium currents of rods and large single cones by 44 and 48%, respectively. Thus functional CB1 receptors, present in the terminals of rod and cone photoreceptors, differentially modulate calcium and potassium currents in rods and large single cones. CB1 receptors are therefore well positioned to modulate neurotransmitter release at the first synapse of the visual system.

  4. Evaluation of the In Vivo and Ex Vivo Binding of Novel BC1 Cannabinoid Receptor Radiotracers

    SciTech Connect

    Miller, A.; Gatley, J.; Gifford, A.

    2002-01-01

    The primary active ingredient of marijuana, 9-tetrahydrocannabinol, exerts its psychoactive effects by binding to cannabinoid CB1 receptors. These receptors are found throughout the brain with high concentrations in the hippocampus and cerebellum. The current study was conducted to evaluate the binding of a newly developed putative cannabinoid antagonist, AM630, and a classical cannabinoid 8-tetrahydrocannabinol as potential PET and/or SPECT imaging agents for brain CB1 receptors. For both of these ligands in vivo and ex vivo studies in mice were conducted. AM630 showed good overall brain uptake (as measure by %IA/g) and a moderately rapid clearance from the brain with a half-clearance time of approximately 30 minutes. However, AM630 did not show selective binding to CB1 cannabinoid receptors. Ex vivo autoradiography supported the lack of selective binding seen in the in vivo study. Similar to AM630, 8-tetrahydrocanibol also failed to show selective binding to CB1 receptor rich brain areas. The 8-tetrahydrocanibol showed moderate overall brain uptake and relatively slow brain clearance as compared to AM630. Further studies were done with AM2233, a cannabinoid ligand with a similar structure as AM630. These studies were done to develop an ex vivo binding assay to quantify the displacement of [131I]AM2233 binding by other ligands in Swiss-Webster and CB1 receptor knockout mice. By developing this assay we hoped to determine the identity of an unknown binding site for AM2233 present in the hippocampus of CB1 knockout mice. Using an approach based on incubation of brain slices prepared from mice given intravenous [131I]AM2233 in either the presence or absence of AM2233 (unlabelled) it was possible to demonstrate a significant AM2233-displacable binding in the Swiss-Webster mice. Future studies will determine if this assay is appropriate for identifying the unknown binding site for AM2233 in the CB1 knockout mice.

  5. Differential Effects of Cannabinoid Receptor Agonist on Social Discrimination and Contextual Fear in Amygdala and Hippocampus

    ERIC Educational Resources Information Center

    Segev, Amir; Akirav, Irit

    2011-01-01

    We examined whether the cannabinoid receptor agonist WIN55,212-2 (WIN; 5 [mu]g/side) microinjected into the hippocampus or the amygdala would differentially affect memory processes in a neutral vs. an aversive task. In the aversive contextual fear task, WIN into the basolateral amygdala impaired fear acquisition/consolidation, but not retrieval.…

  6. CB1 Cannabinoid Receptors Modulate Kinase and Phosphatase Activity during Extinction of Conditioned Fear in Mice

    ERIC Educational Resources Information Center

    Kamprath, Kornelia; Hermann, Heike; Lutz, Beat; Marsicano, Giovanni; Cannich, Astrid; Wotjak, Carsten T.

    2004-01-01

    Cannabinoid receptors type 1 (CB1) play a central role in both short-term and long-term extinction of auditory-cued fear memory. The molecular mechanisms underlying this function remain to be clarified. Several studies indicated extracellular signal-regulated kinases (ERKs), the phosphatidylinositol 3-kinase with its downstream effector AKT, and…

  7. Deficits in Sensory-Specific Devaluation Task Performance Following Genetic Deletions of Cannabinoid (CB1) Receptor

    ERIC Educational Resources Information Center

    Crombag, Hans S.; Johnson, Alexander W.; Zimmer, Anne M.; Zimmer, Andreas; Holland, Peter C.

    2010-01-01

    Cannabinoid CB1 receptor is abundantly expressed throughout the CNS and is implicated in numerous physiological and behavioral functions, including appetite and feeding. In the present study, wild-type and CB1 heterozygous and homozygous knockout mice were tested on an instrumental outcome-selective devaluation task to assess changes in acquired…

  8. Evidence for an interaction between CB1 cannabinoid and oxytocin receptors in food and water intake.

    PubMed

    Verty, A N A; McFarlane, J R; McGregor, I S; Mallet, P E

    2004-09-01

    Oxytocin and CB(1) cannabinoid receptors independently modulate food intake. Although an interaction between oxytocin and cannabinoid systems has been demonstrated with respect to the cannabinoid withdrawal syndrome, the interaction between these systems in modulating food intake has not yet been examined. The present study had three primary purposes: (1) to determine whether oxytocin and a CB(1) receptor antagonist block food and fluid intake in a supra-additive manner, (2) to determine the relative position of the CB(1) receptors in the chain of control of food intake in relation to the oxytocin system, and (3) to determine whether the increase in fluid intake induced by an oxytocin antagonist is mediated via cannabinoid receptors. Rats were habituated to the test environment and injection procedure, and then received intracerebroventricular (ICV) injections of various combinations of the oxytocin receptor antagonist tocinoic acid, the cannabionid receptor agonist delta(9)-tetrahydrocannabinol (THC), oxytocin, or the cannabinoid receptor antagonist SR 141716. Food and water intake and locomotor activity were then measured for 120 min. When administrated alone, SR 141716 and oxytocin dose-dependently attenuated baseline food intake, while oxytocin but not SR 141716 reduced water intake. Sub-anorectic doses of SR 141716 and oxytocin attenuated baseline feeding beyond what would be expected by the sum of the individual drug effects without affecting baseline water intake. THC stimulated feeding but not water intake. THC-induced feeding was not blocked by oxytocin, however, the oxytocin did attenuate water intake during such feeding. SR 141716 dose-dependently reduced tocinoic-acid-stimulated food intake and partially attenuated water intake. Locomotor activity was not significantly affected by any drug treatments, suggesting that effects on feeding were not due to a non-specific reduction in motivated behaviour. These findings reveal an interaction between

  9. Cannabinoid receptors CB1 and CB2 form functional heteromers in brain.

    PubMed

    Callén, Lucía; Moreno, Estefanía; Barroso-Chinea, Pedro; Moreno-Delgado, David; Cortés, Antoni; Mallol, Josefa; Casadó, Vicent; Lanciego, José Luis; Franco, Rafael; Lluis, Carmen; Canela, Enric I; McCormick, Peter J

    2012-06-15

    Exploring the role of cannabinoid CB(2) receptors in the brain, we present evidence of CB(2) receptor molecular and functional interaction with cannabinoid CB(1) receptors. Using biophysical and biochemical approaches, we discovered that CB(2) receptors can form heteromers with CB(1) receptors in transfected neuronal cells and in rat brain pineal gland, nucleus accumbens, and globus pallidus. Within CB(1)-CB(2) receptor heteromers expressed in a neuronal cell model, agonist co-activation of CB(1) and CB(2) receptors resulted in a negative cross-talk in Akt phosphorylation and neurite outgrowth. Moreover, one specific characteristic of CB(1)-CB(2) receptor heteromers consists of both the ability of CB(1) receptor antagonists to block the effect of CB(2) receptor agonists and, conversely, the ability of CB(2) receptor antagonists to block the effect of CB(1) receptor agonists, showing a bidirectional cross-antagonism phenomenon. Taken together, these data illuminate the mechanism by which CB(2) receptors can negatively modulate CB(1) receptor function.

  10. The role of cannabinoids in adult neurogenesis

    PubMed Central

    Prenderville, Jack A; Kelly, Áine M; Downer, Eric J

    2015-01-01

    The processes underpinning post-developmental neurogenesis in the mammalian brain continue to be defined. Such processes involve the proliferation of neural stem cells and neural progenitor cells (NPCs), neuronal migration, differentiation and integration into a network of functional synapses within the brain. Both intrinsic (cell signalling cascades) and extrinsic (neurotrophins, neurotransmitters, cytokines, hormones) signalling molecules are intimately associated with adult neurogenesis and largely dictate the proliferative activity and differentiation capacity of neural cells. Cannabinoids are a unique class of chemical compounds incorporating plant-derived cannabinoids (the active components of Cannabis sativa), the endogenous cannabinoids and synthetic cannabinoid ligands, and these compounds are becoming increasingly recognized for their roles in neural developmental processes. Indeed, cannabinoids have clear modulatory roles in adult neurogenesis, probably through activation of both CB1 and CB2 receptors. In recent years, a large body of literature has deciphered the signalling networks involved in cannabinoid-mediated regulation of neurogenesis. This timely review summarizes the evidence that the cannabinoid system is intricately associated with neuronal differentiation and maturation of NPCs and highlights intrinsic/extrinsic signalling mechanisms that are cannabinoid targets. Overall, these findings identify the central role of the cannabinoid system in adult neurogenesis in the hippocampus and the lateral ventricles and hence provide insight into the processes underlying post-developmental neurogenesis in the mammalian brain. PMID:25951750

  11. 1-Benzhydryl-3-phenylurea and 1-benzhydryl-3-phenylthiourea derivatives: new templates among the CB1 cannabinoid receptor inverse agonists.

    PubMed

    Muccioli, Giulio G; Wouters, Johan; Scriba, Gerhard K E; Poppitz, Wolfgang; Poupaert, Jacques H; Lambert, Didier M

    2005-11-17

    New 1-benzhydryl-3-phenylurea derivatives and their 1-benzhydryl-3-phenylthiourea isosteres were synthesized and evaluated for their human CB1 and CB2 cannabinoid receptor affinity. These compounds proved to be selective CB1 cannabinoid receptor ligands, acting as inverse agonists in a [35S]-GTPgammaS assay. The affinity of 3,5,5'-triphenylimidazolidine-2,4-dione and 3,5,5'-triphenyl-2-thioxoimidazolidin-4-one derivatives, possessing the 1-benzhydryl-3-phenylurea and 1-benzhydryl-3-phenylthiourea moiety, respectively, was also evaluated. In conclusion, the 1-benzhydryl-3-phenylurea scaffold seems to be a new interesting template of CB1 cannabinoid receptor inverse agonists.

  12. Genetic variations in the human cannabinoid receptor gene are associated with happiness.

    PubMed

    Matsunaga, Masahiro; Isowa, Tokiko; Yamakawa, Kaori; Fukuyama, Seisuke; Shinoda, Jun; Yamada, Jitsuhiro; Ohira, Hideki

    2014-01-01

    Happiness has been viewed as a temporary emotional state (e.g., pleasure) and a relatively stable state of being happy (subjective happiness level). As previous studies demonstrated that individuals with high subjective happiness level rated their current affective states more positively when they experience positive events, these two aspects of happiness are interrelated. According to a recent neuroimaging study, the cytosine to thymine single-nucleotide polymorphism of the human cannabinoid receptor 1 gene is associated with sensitivity to positive emotional stimuli. Thus, we hypothesized that our genetic traits, such as the human cannabinoid receptor 1 genotypes, are closely related to the two aspects of happiness. In Experiment 1, 198 healthy volunteers were used to compare the subjective happiness level between cytosine allele carriers and thymine-thymine carriers of the human cannabinoid receptor 1 gene. In Experiment 2, we used positron emission tomography with 20 healthy participants to compare the brain responses to positive emotional stimuli of cytosine allele carriers to that of thymine-thymine carriers. Compared to thymine-thymine carriers, cytosine allele carriers have a higher subjective happiness level. Regression analysis indicated that the cytosine allele is significantly associated with subjective happiness level. The positive mood after watching a positive film was significantly higher for the cytosine allele carriers compared to the thymine-thymine carriers. Positive emotion-related brain region such as the medial prefrontal cortex was significantly activated when the cytosine allele carriers watched the positive film compared to the thymine-thymine carriers. Thus, the human cannabinoid receptor 1 genotypes are closely related to two aspects of happiness. Compared to thymine-thymine carriers, the cytosine allele carriers of the human cannabinoid receptor 1 gene, who are sensitive to positive emotional stimuli, exhibited greater magnitude

  13. Predicting the molecular interactions of CRIP1a-cannabinoid 1 receptor with integrated molecular modeling approaches.

    PubMed

    Ahmed, Mostafa H; Kellogg, Glen E; Selley, Dana E; Safo, Martin K; Zhang, Yan

    2014-02-15

    Cannabinoid receptors are a family of G-protein coupled receptors that are involved in a wide variety of physiological processes and diseases. One of the key regulators that are unique to cannabinoid receptors is the cannabinoid receptor interacting proteins (CRIPs). Among them CRIP1a was found to decrease the constitutive activity of the cannabinoid type-1 receptor (CB1R). The aim of this study is to gain an understanding of the interaction between CRIP1a and CB1R through using different computational techniques. The generated model demonstrated several key putative interactions between CRIP1a and CB1R, including the critical involvement of Lys130 in CRIP1a.

  14. Elucidating Cannabinoid Biology in Zebrafish (Danio rerio)

    PubMed Central

    Krug, Randall G.; Clark, Karl J.

    2015-01-01

    The number of annual cannabinoid users exceeds 100,000,000 globally and an estimated 9 % of these individuals will suffer from dependency. Although exogenous cannabinoids, like those contained in marijuana, are known to exert their effects by disrupting the endocannabinoid system, a dearth of knowledge exists about the potential toxicological consequences on public health. Conversely, the endocannabinoid system represents a promising therapeutic target for a plethora of disorders because it functions to endogenously regulate a vast repertoire of physiological functions. Accordingly, the rapidly expanding field of cannabinoid biology has sought to leverage model organisms in order to provide both toxicological and therapeutic insights about altered endocannabinoid signaling. The primary goal of this manuscript is to review the existing field of cannabinoid research in the genetically tractable zebrafish model—focusing on the cannabinoid receptor genes, cnr1 and cnr2, and the genes that produce enzymes for synthesis and degradation of the cognate ligands anandamide and 2-arachidonylglycerol. Consideration is also given to research that has studied the effects of exposure to exogenous phytocannabinoids and synthetic cannabinoids that are known to interact with cannabinoid receptors. These results are considered in the context of either endocannabinoid gene expression or endocannabinoid gene function, and are integrated with findings from rodent studies. This provides the framework for a discussion of how zebrafish may be leveraged in the future to provide novel toxicological and therapeutic insights in the field of cannabinoid biology, which has become increasingly significant given recent trends in cannabis legislation. PMID:26192460

  15. Cannabinoid receptor activation inhibits cell cycle progression by modulating 14-3-3β.

    PubMed

    Jung, Hye-Won; Park, Inae; Ghil, Sungho

    2014-09-01

    Cannabinoids display various pharmacological activities, including tumor regression, anti-inflammatory and neuroprotective effects. To investigate the molecular mechanisms underlying the pharmacological effects of cannabinoids, we used a yeast two-hybrid system to screen a mouse brain cDNA library for proteins interacting with type 1 cannabinoid receptor (CB1R). Using the intracellular loop 3 of CB1R as bait, we identified 14-3-3β as an interacting partner of CB1R and confirmed their interaction using affinity-binding assays. 14-3-3β has been reported to induce a cell cycle delay at the G2/M phase. We tested the effects of cannabinoids on cell cycle progression in HeLa cells synchronized using a double-thymidine block-and-release protocol and found an increase in the population of G2/M phase cells. We further found that CB1R activation augmented the interaction of 14-3-3β with Wee1 and Cdc25B, and promoted phosphorylation of Cdc2 at Tyr-15. These results suggest that cannabinoids induce cell cycle delay at the G2/M phase by activating 14-3-3β.

  16. Cannabinoids: mechanisms and therapeutic applications in the CNS.

    PubMed

    Drysdale, Alison J; Platt, Bettina

    2003-12-01

    Cannabinoids comprise three classes of compounds, the active components of marijuana (Cannabis sativa), as well as endogenous and synthetic derivatives. To date, two distinct cannabinoid receptors (CB1 and CB2) have been discovered, but evidence for further receptor types has been brought forward. The potential use of cannabinoids for medicinal purposes has long been known, but the mechanisms of action of both exogenously applied and endogenous cannabinoids are only partly established. For nervous system disorders, cannabinoids may be useful by modulating neurotransmission and calcium homeostasis as well as by anti-inflammatory and anti-oxidant actions. Some cannabinoids can also trigger cell death, which may be of therapeutic benefit in the treatment of malignant tumours. A number of both in vitro and in vivo models have provided promising but diverse evidence for cannabinoid protection in glutamate-mediated excitotoxicity, hypoxia and glucose deprivation, brain trauma, epilepsy and MS. Subsequent to many preclinical investigations, clinical trials are now underway in a variety of the above applications. Overall, the understanding of the therapeutic relevance of cannabinoids will rely on further investigations into the neuroprotective and neurotoxic potency of cannabinoids in animal models and humans, as much as on a further advancement of our general understanding of the endocannabinoid system and the development of specific compounds devoid of unwanted psychoactive side effects.

  17. Selective Estrogen Receptor Modulators: Cannabinoid Receptor Inverse Agonists with Differential CB1 and CB2 Selectivity

    PubMed Central

    Franks, Lirit N.; Ford, Benjamin M.; Prather, Paul L.

    2016-01-01

    Selective estrogen receptor modulators (SERMs) are used to treat estrogen receptor (ER)-positive breast cancer and osteoporosis. Interestingly, tamoxifen and newer classes of SERMs also exhibit cytotoxic effects in cancers devoid of ERs, indicating a non-estrogenic mechanism of action. Indicative of a potential ER-independent target, reports demonstrate that tamoxifen binds to cannabinoid receptors (CBRs) with affinity in the low μM range and acts as an inverse agonist. To identify cannabinoids with improved pharmacological properties relative to tamoxifen, and further investigate the use of different SERM scaffolds for future cannabinoid drug development, this study characterized the affinity and activity of SERMs in newer structural classes at CBRs. Fourteen SERMs from five structurally distinct classes were screened for binding to human CBRs. Compounds from four of five SERM classes examined bound to CBRs. Subsequent studies fully characterized CBR affinity and activity of one compound from each class. Ospemifine (a triphenylethylene) selectively bound to CB1Rs, while bazedoxifine (an indole) bound to CB2Rs with highest affinity. Nafoxidine (a tetrahydronaphthalene) and raloxifene (RAL; a benzothiaphene) bound to CB1 and CB2Rs non-selectively. All four compounds acted as inverse agonists at CB1 and CB2Rs, reducing basal G-protein activity with IC50 values in the nM to low μM range. Ospemifine, bazedoxifene and RAL also acted as inverse agonists to elevate basal intracellular cAMP levels in intact CHO-hCB2 cells. The four SERMs examined also acted as CB1 and CB2R antagonists in the cAMP assay, producing rightward shifts in the concentration-effect curve of the CBR agonist CP-55,940. In conclusion, newer classes of SERMs exhibit improved pharmacological characteristics (e.g., in CBR affinity and selectivity) relative to initial studies with tamoxifen, and thus suggest that different SERM scaffolds may be useful for development of safe and selective drugs acting

  18. A restricted population of CB1 cannabinoid receptors with neuroprotective activity.

    PubMed

    Chiarlone, Anna; Bellocchio, Luigi; Blázquez, Cristina; Resel, Eva; Soria-Gómez, Edgar; Cannich, Astrid; Ferrero, José J; Sagredo, Onintza; Benito, Cristina; Romero, Julián; Sánchez-Prieto, José; Lutz, Beat; Fernández-Ruiz, Javier; Galve-Roperh, Ismael; Guzmán, Manuel

    2014-06-03

    The CB1 cannabinoid receptor, the main molecular target of endocannabinoids and cannabis active components, is the most abundant G protein-coupled receptor in the mammalian brain. Of note, CB1 receptors are expressed at the synapses of two opposing (i.e., GABAergic/inhibitory and glutamatergic/excitatory) neuronal populations, so the activation of one and/or another receptor population may conceivably evoke different effects. Despite the widely reported neuroprotective activity of the CB1 receptor in animal models, the precise pathophysiological relevance of those two CB1 receptor pools in neurodegenerative processes is unknown. Here, we first induced excitotoxic damage in the mouse brain by (i) administering quinolinic acid to conditional mutant animals lacking CB1 receptors selectively in GABAergic or glutamatergic neurons, and (ii) manipulating corticostriatal glutamatergic projections remotely with a designer receptor exclusively activated by designer drug pharmacogenetic approach. We next examined the alterations that occur in the R6/2 mouse, a well-established model of Huntington disease, upon (i) fully knocking out CB1 receptors, and (ii) deleting CB1 receptors selectively in corticostriatal glutamatergic or striatal GABAergic neurons. The data unequivocally identify the restricted population of CB1 receptors located on glutamatergic terminals as an indispensable player in the neuroprotective activity of (endo)cannabinoids, therefore suggesting that this precise receptor pool constitutes a promising target for neuroprotective therapeutic strategies.

  19. Beneficial effects of cannabinoids (CB) in a murine model of allergen-induced airway inflammation: role of CB1/CB2 receptors.

    PubMed

    Braun, Andrea; Engel, Tabea; Aguilar-Pimentel, Juan Antonio; Zimmer, Andreas; Jakob, Thilo; Behrendt, Heidrun; Mempel, Martin

    2011-04-01

    The endocannabinoid system (ECS) consists of two cannabinoid (CB) receptors, namely CB(1) and CB(2) receptor, and their endogenous (endocannabinoids) and exogenous (cannabinoids, e.g. delta-9-tetrahydrocannabinol (THC)) ligands which bind to these receptors. Based on studies suggesting a role of THC and the ECS in inflammation, the objective of this study was to examine their involvement in type I hypersensitivity using a murine model of allergic airway inflammation. THC treatment of C57BL/6 wildtype mice dramatically reduced airway inflammation as determined by significantly reduced total cell counts in bronchoalveolar lavage (BAL). These effects were greatest when mice were treated during both, the sensitization and the challenge phase. Furthermore, systemic immune responses were significantly suppressed in mice which received THC during sensitization phase. To investigate a role of CB(1/2) receptors in this setting, we used pharmacological blockade of CB(1) and/or CB(2) receptors by the selective antagonists and moreover CB(1)/CB(2) receptor double-knockout mice (CB(1)(-/-)/CB(2)(-/-)) and found neither significant changes in the cell patterns in BAL nor in immunoglobulin levels as compared to wildtype mice. Our results indicate that the activation of the ECS by applying the agonist THC is involved in the development of type I allergies. However, CB(1)/CB(2) receptor-independent signalling seems likely in the observed results.

  20. Cannabinoid CB2 receptors: a therapeutic target for the treatment of inflammatory and neuropathic pain

    PubMed Central

    Guindon, J; Hohmann, A G

    2007-01-01

    Cannabinoids suppress behavioural responses to noxious stimulation and suppress nociceptive transmission through activation of CB1 and CB2 receptor subtypes. CB1 receptors are expressed at high levels in the central nervous system (CNS), whereas CB2 receptors are found predominantly, but not exclusively, outside the CNS. CB2 receptors are also upregulated in the CNS and dorsal root ganglia by pathological pain states. Here, we review behavioural, neurochemical and electrophysiological data, which identify cannabinoid CB2 receptors as a therapeutic target for treating pathological pain states with limited centrally, mediated side effects. The development of CB2-selective agonists (with minimal affinity for CB1) as well as mutant mice lacking CB2 receptors has provided pharmacological and genetic tools required to evaluate the effectiveness of CB2 agonists in suppressing persistent pain states. This review will examine the efficacy of cannabinoid CB2-selective agonists in suppressing acute, inflammatory and neuropathic nociception following systemic and local routes of administration. Data derived from behavioural, neurochemical and neurophysiological approaches are discussed to better understand the relationship between antinociceptive effects induced by CB2-selective agonists in behavioural studies and neural mechanisms of pain suppression. Finally, the therapeutic potential and possible limitations of CB2-based pharmacotherapies for pathological pain states induced by tissue and nerve injury are discussed. PMID:17994113

  1. Involvement of central and peripheral cannabinoid receptors on antinociceptive effect of tetrahydrocannabinol in muscle pain.

    PubMed

    Bagüés, Ana; Martín, M Isabel; Sánchez-Robles, Eva M

    2014-12-15

    Cannabinoid (CB) receptors have emerged as an attractive therapeutic target for pain management in recent years and the interest in the use of cannabinoids is gradually increasing, particularly in patients where conventional treatments fail. Muscle pain is a major clinical problem and new pharmacological approaches are being studied. Recently, we have demonstrated that cannabinoid synthetic agonists are useful to reduce muscular pain in two animal models, where the local administration is effective. Now, we want to know if tetrahydrocannabinol (THC), a cannabinoid natural derivative with therapeutic use in humans, is also effective in reducing acute muscle pain. The antinociceptive effect of THC by systemic (i.p.) and local (i.m.) administration was tested in two animal models of acute muscle pain, rat masseter and gastrocnemius, induced by hypertonic saline (HS) injection. The drugs used were the non-selective agonist THC and two selective cannabinoid antagonists, AM251 (CB1) and AM630 (CB2). THC, i.p. and i.m. administered, reduced the nociceptive behaviours induced by HS in both muscular pain models. The antinociceptive effect induced by the systemic administration of THC was mediated by CB1 receptors in the masseter muscle whereas in gastrocnemius both CB1 and CB2 receptors participated. When THC was administered locally, only CB2 receptors were involved in the antinociceptive effect in both muscles. This study suggests that THC could be a future pharmacological option in the treatment of muscle pain. The local administration of THC could be an interesting option to treat this type of pain avoiding the central adverse effects.

  2. Primary Macrophage Chemotaxis Induced by Cannabinoid Receptor 2 Agonists Occurs Independently of the CB2 Receptor.

    PubMed

    Taylor, Lewis; Christou, Ivy; Kapellos, Theodore S; Buchan, Alice; Brodermann, Maximillian H; Gianella-Borradori, Matteo; Russell, Angela; Iqbal, Asif J; Greaves, David R

    2015-06-02

    Activation of CB2 has been demonstrated to induce directed immune cell migration. However, the ability of CB2 to act as a chemoattractant receptor in macrophages remains largely unexplored. Using a real-time chemotaxis assay and a panel of chemically diverse and widely used CB2 agonists, we set out to examine whether CB2 modulates primary murine macrophage chemotaxis. We report that of 12 agonists tested, only JWH133, HU308, L-759,656 and L-759,633 acted as macrophage chemoattractants. Surprisingly, neither pharmacological inhibition nor genetic ablation of CB2 had any effect on CB2 agonist-induced macrophage chemotaxis. As chemotaxis was pertussis toxin sensitive in both WT and CB2(-/-) macrophages, we concluded that a non-CB1/CB2, Gi/o-coupled GPCR must be responsible for CB2 agonist-induced macrophage migration. The obvious candidate receptors GPR18 and GPR55 could not mediate JWH133 or HU308-induced cytoskeletal rearrangement or JWH133-induced β-arrestin recruitment in cells transfected with either receptor, demonstrating that neither are the unidentified GPCR. Taken together our results conclusively demonstrate that CB2 is not a chemoattractant receptor for murine macrophages. Furthermore we show for the first time that JWH133, HU308, L-759,656 and L-759,633 have off-target effects of functional consequence in primary cells and we believe that our findings have wide ranging implications for the entire cannabinoid field.

  3. Primary Macrophage Chemotaxis Induced by Cannabinoid Receptor 2 Agonists Occurs Independently of the CB2 Receptor

    PubMed Central

    Taylor, Lewis; Christou, Ivy; Kapellos, Theodore S.; Buchan, Alice; Brodermann, Maximillian H.; Gianella-Borradori, Matteo; Russell, Angela; Iqbal, Asif J.; Greaves, David R.

    2015-01-01

    Activation of CB2 has been demonstrated to induce directed immune cell migration. However, the ability of CB2 to act as a chemoattractant receptor in macrophages remains largely unexplored. Using a real-time chemotaxis assay and a panel of chemically diverse and widely used CB2 agonists, we set out to examine whether CB2 modulates primary murine macrophage chemotaxis. We report that of 12 agonists tested, only JWH133, HU308, L-759,656 and L-759,633 acted as macrophage chemoattractants. Surprisingly, neither pharmacological inhibition nor genetic ablation of CB2 had any effect on CB2 agonist-induced macrophage chemotaxis. As chemotaxis was pertussis toxin sensitive in both WT and CB2-/- macrophages, we concluded that a non-CB1/CB2, Gi/o-coupled GPCR must be responsible for CB2 agonist-induced macrophage migration. The obvious candidate receptors GPR18 and GPR55 could not mediate JWH133 or HU308-induced cytoskeletal rearrangement or JWH133-induced β-arrestin recruitment in cells transfected with either receptor, demonstrating that neither are the unidentified GPCR. Taken together our results conclusively demonstrate that CB2 is not a chemoattractant receptor for murine macrophages. Furthermore we show for the first time that JWH133, HU308, L-759,656 and L-759,633 have off-target effects of functional consequence in primary cells and we believe that our findings have wide ranging implications for the entire cannabinoid field. PMID:26033291

  4. Evidence for association between polymorphisms in the Cannabinoid Receptor 1 (CNR1) gene and cannabis dependence

    PubMed Central

    Agrawal, Arpana; Wetherill, Leah; Dick, Danielle M.; Xuei, Xiaoling; Hinrichs, Anthony; Hesselbrock, Victor; Kramer, John; Nurnberger, John I.; Schuckit, Marc; Bierut, Laura J.; Edenberg, Howard J.; Foroud, Tatiana

    2009-01-01

    Genomic studies of cannabis use disorders have been limited. The cannabinoid receptor 1 gene (CNR1) on chromosome 6q14–15 is an excellent candidate gene for cannabis dependence due to the important role of the G-protein coupled receptor encoded by this gene in the rewarding effects of Δ9-tetrahydrocannabinol. Previous studies have found equivocal evidence for an association between SNPs in CNR1 and a general vulnerability to substance use disorders. We investigate the association between 9 SNPs spanning CNR1 and cannabis dependence in 1,923 individuals. Two SNPs that were previously associated with cannabis dependence in other studies were also significant with this phenotype in our analyses [rs806368 (p = 0.05) and rs806380 (p = 0.009)]. Haplotype analyses revealed the association to be largely driven by the SNP rs806380. These results suggest a role for the cannabinoid receptor 1 gene in cannabis dependence. PMID:19016476

  5. Cannabinoid CB2 receptor attenuates morphine-induced inflammatory responses in activated microglial cells

    PubMed Central

    Merighi, Stefania; Gessi, Stefania; Varani, Katia; Fazzi, Debora; Mirandola, Prisco; Borea, Pier Andrea

    2012-01-01

    BACKGROUND AND PURPOSE Among several pharmacological properties, analgesia is the most common feature shared by either opioid or cannabinoid systems. Cannabinoids and opioids are distinct drug classes that have been historically used separately or in combination to treat different pain states. In the present study, we characterized the signal transduction pathways mediated by cannabinoid CB2 and µ-opioid receptors in quiescent and LPS-stimulated murine microglial cells. EXPERIMENTAL APPROACH We examined the effects of µ-opioid and CB2 receptor stimulation on phosphorylation of MAPKs and Akt and on IL-1β, TNF-α, IL-6 and NO production in primary mouse microglial cells. KEY RESULTS Morphine enhanced release of the proinflammatory cytokines, IL-1β, TNF-α, IL-6, and of NO via µ-opioid receptor in activated microglial cells. In contrast, CB2 receptor stimulation attenuated morphine-induced microglial proinflammatory mediator increases, interfering with morphine action by acting on the Akt-ERK1/2 signalling pathway. CONCLUSIONS AND IMPLICATIONS Because glial activation opposes opioid analgesia and enhances opioid tolerance and dependence, we suggest that CB2 receptors, by inhibiting microglial activity, may be potential targets to increase clinical efficacy of opioids. PMID:22428664

  6. Cannabinoid receptor-regulated cyclic AMP accumulation in the rat striatum.

    PubMed

    Bidaut-Russell, M; Howlett, A C

    1991-11-01

    The present study demonstrates that desacetyllevonantradol, a synthetic cannabinoid analog, reduces cyclic AMP levels in rat striatal slices stimulated with vasoactive intestinal peptide or SKF 38393, a D1-dopamine agonist. Desacetyllevonantradol and the D2 agonist LY 171555 both inhibited D1-stimulated cyclic AMP accumulation in the striatum. Spiperone, a specific D2-dopamine antagonist, fully reversed the inhibitory effect of LY 171555 but not that of desacetyllevonantradol, indicating that this cannabinoid response is not occurring through a D2-dopaminergic mechanism. Morphine also inhibited cyclic AMP accumulation in striatal slices stimulated with either SKF 38393 or vasoactive intestinal peptide. Naloxone, an opioid antagonist, fully reversed the effect of morphine but not that of desacetyllevonantradol, indicating that cannabinoid drugs are not acting via a mechanism involving opioid receptors. The response to maximally effective concentrations of desacetyllevonantradol was not additive to that of maximally effective concentrations of either morphine or LY 171555, suggesting that dopaminergic, opioid, and cannabinoid receptors may be present on the same populations of cells.

  7. The dynamic nature of type 1 cannabinoid receptor (CB1) gene transcription

    PubMed Central

    Laprairie, RB; Kelly, MEM; Denovan-Wright, EM

    2012-01-01

    The type 1 cannabinoid receptor (CB1) is an integral component of the endocannabinoid system that modulates several functions in the CNS and periphery. The majority of our knowledge of the endocannabinoid system involves ligand–receptor binding, mechanisms of signal transduction, and protein–protein interactions. In contrast, comparatively little is known about regulation of CB1 gene expression. The levels and anatomical distribution of CB1 mRNA and protein are developmental stage-specific and are dysregulated in several pathological conditions. Moreover, exposure to a variety of drugs, including cannabinoids themselves, alters CB1 gene expression and mRNA levels. As such, alterations in CB1 gene expression are likely to affect the optimal response to cannabinoid-based therapies, which are being developed to treat a growing number of conditions. Here, we will examine the regulation of CB1 mRNA levels and the therapeutic potential inherent in manipulating expression of this gene. Linked Articles This article is part of a themed section on Cannabinoids. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.167.issue-8 PMID:22924606

  8. Small Molecules from Nature Targeting G-Protein Coupled Cannabinoid Receptors: Potential Leads for Drug Discovery and Development

    PubMed Central

    Sharma, Charu; Sadek, Bassem; Goyal, Sameer N.; Sinha, Satyesh; Ojha, Shreesh

    2015-01-01

    The cannabinoid molecules are derived from Cannabis sativa plant which acts on the cannabinoid receptors types 1 and 2 (CB1 and CB2) which have been explored as potential therapeutic targets for drug discovery and development. Currently, there are numerous cannabinoid based synthetic drugs used in clinical practice like the popular ones such as nabilone, dronabinol, and Δ9-tetrahydrocannabinol mediates its action through CB1/CB2 receptors. However, these synthetic based Cannabis derived compounds are known to exert adverse psychiatric effect and have also been exploited for drug abuse. This encourages us to find out an alternative and safe drug with the least psychiatric adverse effects. In recent years, many phytocannabinoids have been isolated from plants other than Cannabis. Several studies have shown that these phytocannabinoids show affinity, potency, selectivity, and efficacy towards cannabinoid receptors and inhibit endocannabinoid metabolizing enzymes, thus reducing hyperactivity of endocannabinoid systems. Also, these naturally derived molecules possess the least adverse effects opposed to the synthetically derived cannabinoids. Therefore, the plant based cannabinoid molecules proved to be promising and emerging therapeutic alternative. The present review provides an overview of therapeutic potential of ligands and plants modulating cannabinoid receptors that may be of interest to pharmaceutical industry in search of new and safer drug discovery and development for future therapeutics. PMID:26664449

  9. Impaired Excitatory Neurotransmission in the Urinary Bladder from the Obese Zucker Rat: Role of Cannabinoid Receptors

    PubMed Central

    Blaha, Igor; Recio, Paz; Martínez, María Pilar; López-Oliva, María Elvira; Ribeiro, Ana S. F.; Agis-Torres, Ángel; Martínez, Ana Cristina; Benedito, Sara; García-Sacristán, Albino; Fernandes, Vítor S.; Hernández, Medardo

    2016-01-01

    Metabolic syndrome (MS) is a known risk factor for lower urinary tract symptoms. This study investigates whether functional and expression changes of cannabinoid CB1 and CB2 receptors are involved in the bladder dysfunction in an obese rat model with insulin resistance. Bladder samples from obese Zucker rat (OZR) and their respective controls lean Zucker rat (LZR) were processed for immunohistochemistry and western blot for studying the cannabinoid receptors expression. Detrusor smooth muscle (DSM) strips from LZR and OZR were also mounted in myographs for isometric force recordings. Neuronal and smooth muscle CB1 and CB2 receptor expression and the nerve fiber density was diminished in the OZR bladder. Electrical field stimulation (EFS) and acetylcholine (ACh) induced frequency- and concentration-dependent contractions of LZR and OZR DSM. ACh contractile responses were similar in LZR and OZR. EFS-elicited contractions, however, were reduced in OZR bladder. Cannabinoid receptor agonists and antagonists failed to modify the DSM basal tension in LZR and OZR In LZR bladder, EFS responses were inhibited by ACEA and SER-601, CB1 and CB2 receptor agonists, respectively, these effects being reversed by ACEA plus the CB1 antagonist, AM-251 or SER-601 plus the CB2 antagonist, AM-630. In OZR bladder, the inhibitory action of ACEA on nerve-evoked contractions was diminished, whereas that SER-601 did not change EFS responses. These results suggest that a diminished function and expression of neuronal cannabinoid CB1 and CB2 receptors, as well as a lower nerve fiber density is involved in the impaired excitatory neurotransmission of the urinary bladder from the OZR. PMID:27285468

  10. Impaired Excitatory Neurotransmission in the Urinary Bladder from the Obese Zucker Rat: Role of Cannabinoid Receptors.

    PubMed

    Blaha, Igor; Recio, Paz; Martínez, María Pilar; López-Oliva, María Elvira; Ribeiro, Ana S F; Agis-Torres, Ángel; Martínez, Ana Cristina; Benedito, Sara; García-Sacristán, Albino; Fernandes, Vítor S; Hernández, Medardo

    2016-01-01

    Metabolic syndrome (MS) is a known risk factor for lower urinary tract symptoms. This study investigates whether functional and expression changes of cannabinoid CB1 and CB2 receptors are involved in the bladder dysfunction in an obese rat model with insulin resistance. Bladder samples from obese Zucker rat (OZR) and their respective controls lean Zucker rat (LZR) were processed for immunohistochemistry and western blot for studying the cannabinoid receptors expression. Detrusor smooth muscle (DSM) strips from LZR and OZR were also mounted in myographs for isometric force recordings. Neuronal and smooth muscle CB1 and CB2 receptor expression and the nerve fiber density was diminished in the OZR bladder. Electrical field stimulation (EFS) and acetylcholine (ACh) induced frequency- and concentration-dependent contractions of LZR and OZR DSM. ACh contractile responses were similar in LZR and OZR. EFS-elicited contractions, however, were reduced in OZR bladder. Cannabinoid receptor agonists and antagonists failed to modify the DSM basal tension in LZR and OZR In LZR bladder, EFS responses were inhibited by ACEA and SER-601, CB1 and CB2 receptor agonists, respectively, these effects being reversed by ACEA plus the CB1 antagonist, AM-251 or SER-601 plus the CB2 antagonist, AM-630. In OZR bladder, the inhibitory action of ACEA on nerve-evoked contractions was diminished, whereas that SER-601 did not change EFS responses. These results suggest that a diminished function and expression of neuronal cannabinoid CB1 and CB2 receptors, as well as a lower nerve fiber density is involved in the impaired excitatory neurotransmission of the urinary bladder from the OZR.

  11. Therapeutic potential of cannabinoid-based drugs.

    PubMed

    Klein, Thomas W; Newton, Catherine A

    2007-01-01

    Cannabinoid-based drugs modeled on cannabinoids originally isolated from marijuana are now known to significantly impact the functioning of the endocannabinoid system of mammals. This system operates not only in the brain but also in organs and tissues in the periphery including the immune system. Natural and synthetic cannabinoids are tricyclic terpenes, whereas the endogenous physiological ligands are eicosanoids. Several receptors for these compounds have been extensively described, CB1 and CB2, and are G protein-coupled receptors; however, cannabinoid-based drugs are also demonstrated to function independently of these receptors. Cannabinoids regulate many physiological functions and their impact on immunity is generally antiinflammatory as powerful modulators of the cytokine cascade. This anti-inflammatory potency has led to the testing of these drugs in chronic inflammatory laboratory paradigms and even in some human diseases. Psychoactive and nonpsychoactive cannabinoid-based drugs such as Delta9-tetrahydrocannabinol, cannabidiol, HU-211, and ajulemic acid have been tested and found moderately effective in clinical trials of multiple sclerosis, traumatic brain injury, arthritis, and neuropathic pain. Furthermore, although clinical trials are not yet reported, preclinical data with cannabinoid-based drugs suggest efficacy in other inflammatory diseases such as inflammatory bowel disease, Alzheimer's disease, atherosclerosis, and osteoporosis.

  12. [Endorphines--the endogenous ligands of opiate receptors (author's transl)].

    PubMed

    Teschemacher, H

    1978-01-01

    The demonstration of opiate receptors in the nervous tissue of vertebrates in 1973 was the starting point of an intensive search for the endogenous ligands of these receptors. During the following years, several of such "edogenous opiates", called "endorphines", were isolated from various tissues of the mammalian organism. These are peptides which are able to elicit the same effects as do opiates. Possibly, they play a role in the reaction of the organism to stress.

  13. The Search for Endogenous Activators of the Aryl Hydrocarbon Receptor

    PubMed Central

    Nguyen, Linh P.; Bradfield, Christopher A.

    2008-01-01

    In its simplest aspect, this review is an attempt to describe the major ligand classes of the aryl hydrocarbon receptor (AHR). A grander objective is to provide models that may help define the physiological activator or “endogenous ligand” of the AHR. We begin by presenting evidence that supports a developmental function for the AHR. This is followed by proposing mechanisms by which an endogenous ligand and consequent AHR activation might be important during normal physiology and development. With this background, we then present a survey of the known xenobiotic, endogenous, dietary and “un-conventional” activators of the AHR. When possible, this includes information about their induction potency, receptor binding affinity and potential for exposure. Because of the essential function of the AHR in embryonic development, we discuss the candidacy of each of these compounds as physiologically important activators. PMID:18076143

  14. Strain differences in the expression of endocannabinoid genes and in cannabinoid receptor binding in the brain of Lewis and Fischer 344 rats.

    PubMed

    Coria, Santiago M; Roura-Martínez, David; Ucha, Marcos; Assis, María Amparo; Miguéns, Miguel; García-Lecumberri, Carmen; Higuera-Matas, Alejandro; Ambrosio, Emilio

    2014-08-04

    The Lewis (LEW) and Fischer 344 (F344) rat strains have been proposed as a model to study certain genetic influences on drug use. These strains differ in terms of the self-administration of several drugs, and in their expression of various components of the dopaminergic, glutamatergic, GABAergic and endogenous opioid neurotransmitter systems. As the endocannabinoid system is linked to these systems, we investigated whether these two strains exhibit differences in cannabinoid receptor binding and in the expression of cannabinoid-related genes. Quantitative autoradiography of [(3)H]-CP 55,940 binding levels and real-time PCR assays were used. F344 rats displayed higher levels of cannabinoid receptor binding in the lateral globus pallidus and weaker CNR1 gene expression in the prefrontal cortex (PFc) than LEW rats. Moreover, the N-acyl phosphatidylethanolamine-specific phospholipase D/fatty acid amide hydrolase ratio was greater in the PFc and NAcc of F344 rats. Our results suggest that the endocannabinoid system may be a mediator of the individual differences that exist in the susceptibility to the rewarding effects of drugs of abuse.

  15. Impact of efficacy at the μ-opioid receptor on antinociceptive effects of combinations of μ-opioid receptor agonists and cannabinoid receptor agonists.

    PubMed

    Maguire, David R; France, Charles P

    2014-11-01

    Cannabinoid receptor agonists, such as Δ(9)-tetrahydrocannabinol (Δ(9)-THC), enhance the antinociceptive effects of μ-opioid receptor agonists, which suggests that combining cannabinoids with opioids would improve pain treatment. Combinations with lower efficacy agonists might be preferred and could avoid adverse effects associated with large doses; however, it is unclear whether interactions between opioids and cannabinoids vary across drugs with different efficacy. The antinociceptive effects of μ-opioid receptor agonists alone and in combination with cannabinoid receptor agonists were studied in rhesus monkeys (n = 4) using a warm water tail withdrawal procedure. Etorphine, fentanyl, morphine, buprenorphine, nalbuphine, Δ(9)-THC, and CP 55,940 (2-[(1R,2R,5R)-5-hydroxy-2-(3-hydroxypropyl) cyclohexyl]-5-(2-methyloctan-2-yl)phenol) each increased tail withdrawal latency. Pretreatment with doses of Δ(9)-THC (1.0 mg/kg) or CP 55,940 (0.032 mg/kg) that were ineffective alone shifted the fentanyl dose-effect curve leftward 20.6- and 52.9-fold, respectively, and the etorphine dose-effect curve leftward 12.4- and 19.6-fold, respectively. Δ(9)-THC and CP 55,940 shifted the morphine dose-effect curve leftward only 3.4- and 7.9-fold, respectively, and the buprenorphine curve only 5.4- and 4.1-fold, respectively. Neither Δ(9)-THC nor CP 55,940 significantly altered the effects of nalbuphine. Cannabinoid receptor agonists increase the antinociceptive potency of higher efficacy opioid receptor agonists more than lower efficacy agonists; however, because much smaller doses of each drug can be administered in combinations while achieving adequate pain relief and that other (e.g., abuse-related) effects of opioids do not appear to be enhanced by cannabinoids, these results provide additional support for combining opioids with cannabinoids to treat pain.

  16. Neuroprotective effect of endogenous cannabinoids on ischemic brain injury induced by the excess microglia-mediated inflammation

    PubMed Central

    Guo, Shuyun; Liu, Yanwu; Ma, Rui; Li, Jun; Su, Binxiao

    2016-01-01

    Increasing evidence has demonstrated the role of endogenous cannabinoids system (ECS) on protecting brain injury caused by ischemia (IMI). Papers reported that microglia-mediated inflammation has become one of the most pivotal mechanisms for IMI. This study was aimed to investigate the potential roles of ECS on neuron protection under microglia-mediated inflammation. Inflammatory cytokines level both in vitro (BV-2 cells) and in vivo (brain tissue from constructed IMI model and brain-isolated microglia) was detected. ECS levels were detected, and its effects on inflammations was also analyzed. Influence of microglia-mediated inflammation on neuron injury was analyzed. Moreover, the effects of ECS on protecting neuron injury were also analyzed. Our results showed that the levels of inflammatory cytokines including TNFα and IL-1β were higher while IKBα was lower in IMI model brain tissue, brain-isolated microglia and BV-2 cells compared to the control. Inflammation was activated in microglia, as well as the activation of ECS characterized by the increasing level of AEA and 2-AG. Furthermore, the activated microglia-mediated self-inflammation performed harmful influence on neurons via suppressing cell viability and inducing apoptosis. Moreover, ECS functioned as a protector on neuron injury though promoting cell proliferation and suppressing cell apoptosis which were caused by the activated BV-2 cells (LPS induced for 3 h). Our data suggested that ECS may play certain neuroprotective effects on microglia-mediated inflammations-induced IMI through anti-inflammatory function. PMID:27398146

  17. Rising stars: modulation of brain functions by astroglial type-1 cannabinoid receptors.

    PubMed

    Metna-Laurent, Mathilde; Marsicano, Giovanni

    2015-03-01

    The type-1-cannabinoid (CB1 ) receptor is amongst the most widely expressed G protein-coupled receptors in the brain. In few decades, CB1 receptors have been shown to regulate a large array of functions from brain cell development and survival to complex cognitive processes. Understanding the cellular mechanisms underlying these functions of CB1 is complex due to the heterogeneity of the brain cell types on which the receptor is expressed. Although the large majority of CB1 receptors act on neurons, early studies pointed to a direct control of CB1 receptors over astroglial functions including brain energy supply and neuroprotection. In line with the growing concept of the tripartite synapse highlighting astrocytes as direct players in synaptic plasticity, astroglial CB1 receptor signaling recently emerged as the mediator of several forms of synaptic plasticity associated to important cognitive functions. Here, we shortly review the current knowledge on CB1 receptor-mediated astroglial functions. This functional spectrum is large and most of the mechanisms by which CB1 receptors control astrocytes, as well as their consequences in vivo, are still unknown, requiring innovative approaches to improve this new cannabinoid research field.

  18. Activation of murine microglial N9 cells is attenuated through cannabinoid receptor CB2 signaling.

    PubMed

    Ma, Lei; Jia, Ji; Liu, Xiangyu; Bai, Fuhai; Wang, Qiang; Xiong, Lize

    2015-02-27

    Inhibition of microglial activation is effective in treating various neurological disorders. Activation of microglial cannabinoid CB2 receptor induces anti-inflammatory effects, and the mechanism, however, is still elusive. Microglia could be activated into the classic activated state (M1 state) or the alternative activated state (M2 state), the former is cytotoxic, and the latter is neurotrophic. In this study, we used lipopolysaccharide (LPS) plus interferon-γ (IFNγ) to activate N9 microglia and hypothesized the pretreatment with cannabinoid CB2 receptor agonist AM1241 attenuates microglial activation by shifting microglial M1 to M2 state. We found that pretreatment with 5 μM AM1241 at 1 h before microglia were exposed to LPS plus IFNγ decreased the expression of inducible nitric oxide synthase (iNOS) and the release of pro-inflammatory factors, increased the expression of arginase 1 (Arg-1) and the release of anti-inflammatory and neurotrophic factors in microglia. However, these effects induced by AM1241 pretreatment were significantly reversed in the presence of 10 μM cannabinoid CB2 receptor antagonist AM630 or 10 μM protein kinase C (PKC) inhibitor chelerythrine. These findings indicated that AM1241 pretreatment attenuates microglial activation by shifting M1 to M2 activated state via CB2 receptor, and the AM1241-induced anti-inflammatory effects may be mediated by PKC.

  19. The role of cannabinoid receptors and the endocannabinoid system in mantle cell lymphoma and other non-Hodgkin lymphomas.

    PubMed

    Wasik, Agata M; Christensson, Birger; Sander, Birgitta

    2011-11-01

    The initiating oncogenic event in mantle cell lymphoma (MCL) is the translocation of cyclin D1, t(11;14)(q13;q32). However, other genetic aberrations are necessary for an overt lymphoma to arise. Like other B cell lymphomas, MCL at some points during the oncogenesis is dependent on interactions with other cells and factors in the microenvironment. The G protein coupled receptors cannabinoid receptors 1 and 2 (CB1 and CB2) are expressed at low levels on non-malignant lymphocytes and at higher levels in MCL and other lymphoma subtypes. In this review we give an overview of what is known on the role of the cannabinoid receptors and their ligands in lymphoma as compared to non-malignant T and B lymphocytes. In MCL cannabinoids mainly reduce cell proliferation and induce cell death. Importantly, our recent findings demonstrate that cannabinoids may induce either apoptosis or another type of programmed cell death, cytoplasmic vacuolation/paraptosis in MCL. The signalling to death has been partly characterized. Even though cannabinoid receptors seem to be expressed in many other types of B cell lymphoma, the functional role of cannabinoid receptor targeting is yet largely unknown. In non-malignant B and T lymphocytes, cannabinoid receptors are up-regulated in response to antigen receptor signalling or CD40. For T lymphocytes IL-4 has also a crucial role in transcriptional regulation of CB1. In lymphocytes, cannabinoid act in several ways - by affecting cell migration, cytokine response, at high doses inhibit cell proliferation and inducing cell death. The possible role for the endocannabinoid system in the immune microenvironment of lymphoma is discussed.

  20. Biased Agonism of Three Different Cannabinoid Receptor Agonists in Mouse Brain Cortex

    PubMed Central

    Diez-Alarcia, Rebeca; Ibarra-Lecue, Inés; Lopez-Cardona, Ángela P.; Meana, Javier; Gutierrez-Adán, Alfonso; Callado, Luis F.; Agirregoitia, Ekaitz; Urigüen, Leyre

    2016-01-01

    Cannabinoid receptors are able to couple to different families of G proteins when activated by an agonist drug. It has been suggested that different intracellular responses may be activated depending on the ligand. The goal of the present study was to characterize the pattern of G protein subunit stimulation triggered by three different cannabinoid ligands, Δ9-THC, WIN55212-2, and ACEA in mouse brain cortex. Stimulation of the [35S]GTPγS binding coupled to specific immunoprecipitation with antibodies against different subtypes of G proteins (Gαi1, Gαi2, Gαi3, Gαo, Gαz, Gαs, Gαq/11, and Gα12/13), in the presence of Δ9-THC, WIN55212-2 and ACEA (submaximal concentration 10 μM) was determined by scintillation proximity assay (SPA) technique in mouse cortex of wild type, CB1 knock-out, CB2 knock-out and CB1/CB2 double knock-out mice. Results show that, in mouse brain cortex, cannabinoid agonists are able to significantly stimulate not only the classical inhibitory Gαi/o subunits but also other G subunits like Gαz, Gαq/11, and Gα12/13. Moreover, the specific pattern of G protein subunit activation is different depending on the ligand. In conclusion, our results demonstrate that, in mice brain native tissue, different exogenous cannabinoid ligands are able to selectively activate different inhibitory and non-inhibitory Gα protein subtypes, through the activation of CB1 and/or CB2 receptors. Results of the present study may help to understand the specific molecular pathways involved in the pharmacological effects of cannabinoid-derived drugs. PMID:27867358

  1. Cannabinoid CB{sub 1} receptor inhibition decreases vascular smooth muscle migration and proliferation

    SciTech Connect

    Rajesh, Mohanraj; Mukhopadhyay, Partha; Hasko, Gyoergy; Pacher, Pal

    2008-12-26

    Vascular smooth muscle proliferation and migration triggered by inflammatory stimuli and chemoattractants such as platelet-derived growth factor (PDGF) are key events in the development and progression of atherosclerosis and restenosis. Cannabinoids may modulate cell proliferation and migration in various cell types through cannabinoid receptors. Here we investigated the effects of CB{sub 1} receptor antagonist rimonabant (SR141716A), which has recently been shown to have anti-atherosclerotic effects both in mice and humans, on PDGF-induced proliferation, migration, and signal transduction of human coronary artery smooth muscle cells (HCASMCs). PDGF induced Ras and ERK 1/2 activation, while increasing proliferation and migration of HCASMCs, which were dose dependently attenuated by CB{sub 1} antagonist, rimonabant. These findings suggest that in addition to improving plasma lipid alterations and decreasing inflammatory cell migration and inflammatory response, CB{sub 1} antagonists may exert beneficial effects in atherosclerosis and restenosis by decreasing vascular smooth muscle proliferation and migration.

  2. Cannabinoid CB₁ receptor is downregulated in clear cell renal cell carcinoma.

    PubMed

    Larrinaga, Gorka; Sanz, Begoña; Pérez, Itxaro; Blanco, Lorena; Cándenas, María L; Pinto, Francisco M; Gil, Javier; López, José I

    2010-12-01

    Several studies in cell cultures and in animal models have demonstrated that cannabinoids have important antitumoral properties. Because many of these effects are mediated through cannabinoid (CB) receptors CB₁ and CB₂, the study of their expression in human neoplasms has become of great interest in recent years. Fresh and formalin-fixed tissue samples of 20 consecutive clear cell renal cell carcinomas (CCRCCs) were collected prospectively and analyzed for the expression of both CB receptors by using RT-PCR, Western blot (WB), and immunohistochemical techniques. RT-PCR assays demonstrated the expression of mRNA encoding the CB₁ in tumor tissue and in adjacent non-neoplastic kidney. Conversely, WB and IHC revealed a marked downregulation of CB₁ protein in tumor tissue; CB₂ was not expressed. The obtained data suggest a possible implication of the endocannabinoid system in renal carcinogenesis. A posttranscriptional downregulation of CB₁ and the absence of expression of CB₂ characterize CCRCC.

  3. Cannabinoid CB(1) receptor expression and affinity in the rat hippocampus following bilateral vestibular deafferentation.

    PubMed

    Baek, Jean Ha; Zheng, Yiwen; Darlington, Cynthia L; Smith, Paul F

    2011-01-10

    Numerous studies have shown that bilateral vestibular deafferentation (BVD) results in spatial memory deficits and hippocampal dysfunction in rats and humans. Since cannabinoid CB(1) receptors are well known to regulate synaptic plasticity in the hippocampus, we investigated whether BVD resulted in changes in CB(1) receptor expression and affinity in the rat hippocampus at 1, 3 and 7 days post-surgery, using a combination of Western blotting and radioligand binding. Using Western blotting, we found that CB(1) receptor expression was significantly lower in BVD animals compared to sham controls only in the CA3 area across the 3 time points (P=0.03). CB(1) receptor expression decreased significantly over time for both the BVD and sham animals (P=0.000). The radioligand binding assays showed no significant change in the IC(50) of the CB(1) receptor for the cannabinoid CB(1)/CB(2) receptor agonist, WIN55,212-2. These results suggest that the CB(1) receptor down-regulates in the CA3 region of the hippocampus following BVD, but with no changes in the affinity of the CB(1) receptor for WIN55,212-2.

  4. Control of spasticity in a multiple sclerosis model using central nervous system-excluded CB1 cannabinoid receptor agonists.

    PubMed

    Pryce, Gareth; Visintin, Cristina; Ramagopalan, Sreeram V; Al-Izki, Sarah; De Faveri, Lia E; Nuamah, Rosamond A; Mein, Charles A; Montpetit, Alexandre; Hardcastle, Alison J; Kooij, Gijs; de Vries, Helga E; Amor, Sandra; Thomas, Sarah A; Ledent, Catherine; Marsicano, Giovanni; Lutz, Beat; Thompson, Alan J; Selwood, David L; Giovannoni, Gavin; Baker, David

    2014-01-01

    The purpose of this study was the generation of central nervous system (CNS)-excluded cannabinoid receptor agonists to test the hypothesis that inhibition of spasticity, due to CNS autoimmunity, could be controlled by affecting neurotransmission within the periphery. Procedures included identification of chemicals and modeling to predict the mode of exclusion; induction and control of spasticity in the ABH mouse model of multiple sclerosis; conditional deletion of CB1 receptor in peripheral nerves; side-effect profiling to demonstrate the mechanism of CNS-exclusion via drug pumps; genome-wide association study in N2(129×ABH) backcross to map polymorphic cannabinoid drug pump; and sequencing and detection of cannabinoid drug-pump activity in human brain endothelial cell lines. Three drugs (CT3, SAB378 and SAD448) were identified that control spasticity via action on the peripheral nerve CB1 receptor. These were peripherally restricted via drug pumps that limit the CNS side effects (hypothermia) of cannabinoids to increase the therapeutic window. A cannabinoid drug pump is polymorphic and functionally lacking in many laboratory (C57BL/6, 129, CD-1) mice used for transgenesis, pharmacology, and toxicology studies. This phenotype was mapped and controlled by 1-3 genetic loci. ABCC1 within a cluster showing linkage is a cannabinoid CNS-drug pump. Global and conditional CB1 receptor-knockout mice were used as controls. In summary, CNS-excluded CB1 receptor agonists are a novel class of therapeutic agent for spasticity.

  5. Immunomodulatory effects of endogenous and synthetic peptides activating opioid receptors.

    PubMed

    Pomorska, Dorota K; Gach, Katarzyna; Janecka, Anna

    2014-01-01

    The main role of endogenous opioid peptides is the modulation of pain. Opioid peptides exert their analgesic activity by binding to the opioid receptors distributed widely in the central nervous system (CNS). However, opioid receptors are also found on tissues and organs outside the CNS, including the cells of the immune system, indicating that opioids are capable of exerting additional effects in periphery. Morphine, which is a gold standard in the treatment of chronic pain, is well-known for its immunosuppressive effects. Much less is known about the immunomodulatory effects exerted by endogenous (enkephalins, endorphins, dynorphins and endomorphins) and synthetic peptides activating opioid receptors. In this review we tried to summarize opioid peptide-mediated modulation of immune cell functions which can be stimulatory as well as inhibitory.

  6. Cortical adrenoceptor expression, function and adaptation under conditions of cannabinoid receptor deletion.

    PubMed

    Reyes, B A S; Carvalho, A F; Szot, P; Kalamarides, D J; Wang, Q; Kirby, L G; Van Bockstaele, E J

    2017-03-21

    A neurochemical target at which cannabinoids interact to have global effects on behavior is brain noradrenergic circuitry. Acute and repeated administration of a cannabinoid receptor synthetic agonist is capable of increasing multiple indices of noradrenergic activity. This includes cannabinoid-induced 1) increases in norepinephrine (NE) release in the medial prefrontal cortex (mPFC); 2) desensitization of cortical α2-adrenoceptor-mediated effects; 3) activation of c-Fos in brainstem locus coeruleus (LC) noradrenergic neurons; and 4) increases in anxiety-like behaviors. In the present study, we sought to examine adaptations in adrenoceptor expression and function under conditions of cannabinoid receptor type 1 (CB1r) deletion using knockout (KO) mice and compare these to wild type (WT) controls. Electrophysiological analysis of α2-adrenoceptor-mediated responses in mPFC slices in WT mice showed a clonidine-induced α2-adrenoceptor-mediated increase in mPFC cell excitability coupled with an increase in input resistance. In contrast, CB1r KO mice showed an α2-adrenoceptor-mediated decrease in mPFC cell excitability. We then examined protein expression levels of α2- and β1-adrenoceptor subtypes in the mPFC as well as TH expression in the locus coeruleus (LC) of mice deficient in CB1r. Both α2- and β1-adrenoceptors exhibited a significant decrease in expression levels in CB1r KO mice when compared to WT in the mPFC, while a significant increase in TH was observed in the LC. To better define whether the same cortical neurons express α2A-adrenoceptor and CB1r in mPFC, we utilized high-resolution immunoelectron microscopy. We localized α2A-adrenoceptors in a knock-in mouse that expressed a hemoagglutinin (HA) tag downstream of the α2A-adrenoceptor promoter. Although the α2A-adrenoceptor was often identified pre-synaptically, we observed co-localization of CB1r with α2-adrenoceptors post-synaptically in the same mPFC neurons. Finally, using receptor binding, we

  7. Effect of the cannabinoid receptor agonist WIN55212-2 on sympathetic cardiovascular regulation

    PubMed Central

    Niederhoffer, Nathalie; Szabo, Bela

    1999-01-01

    The aim of the present study was to analyse the cardiovascular actions of the synthetic CB1/CB2 cannabinoid receptor agonist WIN55212-2, and specifically to determine its sites of action on sympathetic cardiovascular regulation. Pithed rabbits in which the sympathetic outflow was continuously stimulated electrically or which received a pressor infusion of noradrenaline were used to study peripheral prejunctional and direct vascular effects, respectively. For studying effects on brain stem cardiovascular regulatory centres, drugs were administered into the cisterna cerebellomedullaris in conscious rabbits. Overall cardiovascular effects of the cannabinoid were studied in conscious rabbits with intravenous drug administration. In pithed rabbits in which the sympathetic outflow was continuously electrically stimulated, intravenous injection of WIN55212-2 (5, 50 and 500 μg kg−1) markedly reduced blood pressure, the spillover of noradrenaline into plasma and the plasma noradrenaline concentration, and these effects were antagonized by the CB1 cannabinoid receptor-selective antagonist SR141716A. The hypotensive and the sympathoinhibitory effect of WIN55212-2 was shared by CP55940, another mixed CB1/CB2 cannabinoid receptor agonist, but not by WIN55212-3, the enantiomer of WIN55212-2, which lacks affinity for cannabinoid binding sites. WIN55212-2 had no effect on vascular tone established by infusion of noradrenaline in pithed rabbits. Intracisternal application of WIN55212-2 (0.1, 1 and 10 μg kg−1) in conscious rabbits increased blood pressure and the plasma noradrenaline concentration and elicited bradycardia; this latter effect was antagonized by atropine. In conscious animals, intravenous injection of WIN55212-2 (5 and 50 μg kg−1) caused bradycardia, slight hypotension, no change in the plasma noradrenaline concentration, and an increase in renal sympathetic nerve firing. The highest dose of WIN55212-2 (500 μg kg−1) elicited hypotension and

  8. Human metabolites of synthetic cannabinoids JWH-018 and JWH-073 bind with high affinity and act as potent agonists at cannabinoid type-2 receptors

    SciTech Connect

    Rajasekaran, Maheswari; Brents, Lisa K.; Franks, Lirit N.; Moran, Jeffery H.; Prather, Paul L.

    2013-06-01

    K2 or Spice is an emerging drug of abuse that contains synthetic cannabinoids, including JWH-018 and JWH-073. Recent reports indicate that monohydroxylated metabolites of JWH-018 and JWH-073 retain high affinity and activity at cannabinoid type-1 receptors (CB{sub 1}Rs), potentially contributing to the enhanced toxicity of K2 compared to marijuana. Since the parent compounds also bind to cannabinoid type-2 receptors (CB{sub 2}Rs), this study investigated the affinity and intrinsic activity of JWH-018, JWH-073 and several monohydroxylated metabolites at human CB{sub 2}Rs (hCB{sub 2}Rs). The affinity of cannabinoids for hCB{sub 2}Rs was determined by competition binding studies employing CHO-hCB{sub 2} membranes. Intrinsic activity of compounds was assessed by G-protein activation and adenylyl cyclase (AC)-inhibition in CHO-hCB{sub 2} cells. JWH-073, JWH-018 and several of their human metabolites exhibit nanomolar affinity and act as potent agonists at hCB{sub 2}Rs. Furthermore, a major omega hydroxyl metabolite of JWH-073 (JWH-073-M5) binds to CB{sub 2}Rs with 10-fold less affinity than the parent molecule, but unexpectedly, is equipotent in regulating AC-activity when compared to the parent molecule. Finally, when compared to CP-55,940 and Δ{sup 9}-tetrahydrocannabinol (Δ{sup 9}-THC), JWH-018, JWH-018-M5 and JWH-073-M5 require significantly less CB{sub 2}R occupancy to produce similar levels of AC-inhibition, indicating that these compounds may more efficiently couple CB{sub 2}Rs to AC than the well characterized cannabinoid agonists examined. These results indicate that JWH-018, JWH-073 and several major human metabolites of these compounds exhibit high affinity and demonstrate distinctive signaling properties at CB{sub 2}Rs. Therefore, future studies examining pharmacological and toxicological properties of synthetic cannabinoids present in K2 products should consider potential actions of these drugs at both CB{sub 1} and CB{sub 2}Rs. - Highlights: • JWH-018

  9. CB1 and CB2 cannabinoid receptor expression during development and in epileptogenic developmental pathologies.

    PubMed

    Zurolo, E; Iyer, A M; Spliet, W G M; Van Rijen, P C; Troost, D; Gorter, J A; Aronica, E

    2010-09-29

    Recent data support the involvement of the endocannabinoid signaling in early brain development, as well as a key role of cannabinoid receptors (CBR) in pathological conditions associated with unbalanced neuronal excitability and inflammation. Using immunocytochemistry, we explored the expression and cellular pattern of CBR 1 and 2 (CB1 and CB2) during prenatal human cortical development, as well as in focal malformations of cortical development associated with intractable epilepsy (focal cortical dysplasia; cortical tubers in patients with the tuberous sclerosis complex and glioneuronal tumors). Strong CB1 immunoreactivity was detected in the cortical plate in developing human brain from the earliest stages tested (gestational week 9) and it persisted throughout prenatal development. Both cannabinoid receptors were not detected in neural progenitor cells located in the ventricular zone. Only CB1 was expressed in the subventricular zone and in Cajal-Retzius cells in the molecular zone of the developing neocortex. CB2 was detected in cells of the microglia/macrophage lineage during development. In malformations of cortical development, prominent CB1 expression was demonstrated in dysplastic neurons. Both CBR were detected in balloon/giant cells, but CB2 appeared to be more frequently expressed than CB1 in these cell types. Reactive astrocytes were mainly stained with CB1, whereas cells of the microglia/macrophage lineage were stained with CB2. These findings confirm the early expression pattern of cannabinoid receptors in the developing human brain, suggesting a function for CB1 in the early stages of corticogenesis. The expression patterns in malformations of cortical development highlight the role of cannabinoid receptors as mediators of the endocannabinoid signaling and as potential pharmacological targets to modulate neuronal and glial cell function in epileptogenic developmental pathologies.

  10. Cannabinoids as novel anti-inflammatory drugs.

    PubMed

    Nagarkatti, Prakash; Pandey, Rupal; Rieder, Sadiye Amcaoglu; Hegde, Venkatesh L; Nagarkatti, Mitzi

    2009-10-01

    Cannabinoids are a group of compounds that mediate their effects through cannabinoid receptors. The discovery of Δ9-tetrahydrocannabinol (THC) as the major psychoactive principle in marijuana, as well as the identification of cannabinoid receptors and their endogenous ligands, has led to a significant growth in research aimed at understanding the physiological functions of cannabinoids. Cannabinoid receptors include CB1, which is predominantly expressed in the brain, and CB2, which is primarily found on the cells of the immune system. The fact that both CB1 and CB2 receptors have been found on immune cells suggests that cannabinoids play an important role in the regulation of the immune system. Recent studies demonstrated that administration of THC into mice triggered marked apoptosis in T cells and dendritic cells, resulting in immunosuppression. In addition, several studies showed that cannabinoids downregulate cytokine and chemokine production and, in some models, upregulate T-regulatory cells (Tregs) as a mechanism to suppress inflammatory responses. The endocannabinoid system is also involved in immunoregulation. For example, administration of endocannabinoids or use of inhibitors of enzymes that break down the endocannabinoids, led to immunosuppression and recovery from immune-mediated injury to organs such as the liver. Manipulation of endocannabinoids and/or use of exogenous cannabinoids in vivo can constitute a potent treatment modality against inflammatory disorders. This review will focus on the potential use of cannabinoids as a new class of anti-inflammatory agents against a number of inflammatory and autoimmune diseases that are primarily triggered by activated T cells or other cellular immune components.

  11. Exposure to a Highly Caloric Palatable Diet during the Perinatal Period Affects the Expression of the Endogenous Cannabinoid System in the Brain, Liver and Adipose Tissue of Adult Rat Offspring.

    PubMed

    Ramírez-López, María Teresa; Arco, Raquel; Decara, Juan; Vázquez, Mariam; Noemí Blanco, Rosario; Alén, Francisco; Suárez, Juan; Gómez de Heras, Raquel; Rodríguez de Fonseca, Fernando

    2016-01-01

    Recent studies have linked gestational exposure to highly caloric diets with a disrupted endogenous cannabinoid system (ECS). In the present study, we have extended these studies by analyzing the impact of the exposure to a palatable diet during gestation and lactation on a) the adult expression of endocannabinoid-related behaviors, b) the metabolic profile of adult offspring and c) the mRNA expression of the signaling machinery of the ECS in the hypothalamus, the liver and the adipose tissue of adult offspring of both sexes. Exposure to a palatable diet resulted in a) sex-dimorphic and perinatal diet specific feeding behaviors, including the differential response to the inhibitory effects of the cannabinoid receptor inverse agonist AM251, b) features of metabolic syndrome including increased adiposity, hyperleptinemia, hypertriglyceridemia and hypercholesterolemia and c) tissue and sex-specific changes in the expression of both CB1 and CB2 receptors and in that of the endocannabinoid-degrading enzymes FAAH and MAGL, being the adipose tissue the most affected organ analyzed. Since the effects were observed in adult animals that were weaned while consuming a normal diet, the present results indicate that the ECS is one of the targets of maternal programming of the offspring energy expenditure. These results clearly indicate that the maternal diet has long-term effects on the development of pups through multiple alterations of signaling homeostatic pathways that include the ECS. The potential relevance of these alterations for the current obesity epidemic is discussed.

  12. Exposure to a Highly Caloric Palatable Diet during the Perinatal Period Affects the Expression of the Endogenous Cannabinoid System in the Brain, Liver and Adipose Tissue of Adult Rat Offspring

    PubMed Central

    Ramírez-López, María Teresa; Arco, Raquel; Decara, Juan; Vázquez, Mariam; Noemí Blanco, Rosario; Alén, Francisco; Suárez, Juan; Gómez de Heras, Raquel

    2016-01-01

    Recent studies have linked gestational exposure to highly caloric diets with a disrupted endogenous cannabinoid system (ECS). In the present study, we have extended these studies by analyzing the impact of the exposure to a palatable diet during gestation and lactation on a) the adult expression of endocannabinoid-related behaviors, b) the metabolic profile of adult offspring and c) the mRNA expression of the signaling machinery of the ECS in the hypothalamus, the liver and the adipose tissue of adult offspring of both sexes. Exposure to a palatable diet resulted in a) sex-dimorphic and perinatal diet specific feeding behaviors, including the differential response to the inhibitory effects of the cannabinoid receptor inverse agonist AM251, b) features of metabolic syndrome including increased adiposity, hyperleptinemia, hypertriglyceridemia and hypercholesterolemia and c) tissue and sex-specific changes in the expression of both CB1 and CB2 receptors and in that of the endocannabinoid-degrading enzymes FAAH and MAGL, being the adipose tissue the most affected organ analyzed. Since the effects were observed in adult animals that were weaned while consuming a normal diet, the present results indicate that the ECS is one of the targets of maternal programming of the offspring energy expenditure. These results clearly indicate that the maternal diet has long-term effects on the development of pups through multiple alterations of signaling homeostatic pathways that include the ECS. The potential relevance of these alterations for the current obesity epidemic is discussed. PMID:27806128

  13. Sex-dependent effects of periadolescent exposure to the cannabinoid agonist CP-55,940 on morphine self-administration behaviour and the endogenous opioid system.

    PubMed

    Biscaia, Miguel; Fernández, Beatriz; Higuera-Matas, Alejandro; Miguéns, Miguel; Viveros, Maria-Paz; García-Lecumberri, Carmen; Ambrosio, Emilio

    2008-04-01

    Early cannabinoid consumption may predispose individuals to the misuse of addictive drugs later in life. However, there is a lack of experimental evidence as to whether cannabinoid exposure during adolescence might differently affect opiate reinforcing efficacy and the opioid system in adults of both sexes. Our aim was to examine whether periadolescent chronic exposure to the cannabinoid agonist CP-55,940 could exert sex-dependent effects on morphine reinforcing and the opioid system in adulthood. Morphine reinforcing was studied under a progressive ratio (PR) reinforcement schedule in adult male and female rats that previously acquired morphine self-administration under a fixed ratio 1 (FR1) schedule. Binding levels and functionality of mu-opioid receptors were also evaluated. Periadolescent cannabinoid exposure altered morphine self-administration and the opioid system in adult rats in a sex-dependent manner. CP-55,940-exposed males exhibited higher self-administration rates under a FR1, but not under a PR schedule. In females, CP-55,940 did not modify morphine self-administration under either schedule. Moreover, CP-55,940 also increased mu-opioid receptor levels in the subcallosal streak of pre-treated animals and decreased mu-opioid receptor functionality in the nucleus accumbens shell but again, only in males. Our data indicate that adult male rats exposed to the cannabinoid in adolescence self-administer more morphine than females, but only when the demands required by the schedule of reinforcement are low, which might be related to the decrease in mu-opioid receptor functionality in the NAcc-shell observed in these animals.

  14. Estradiol decreases cortical reactive astrogliosis after brain injury by a mechanism involving cannabinoid receptors.

    PubMed

    López Rodríguez, Ana Belén; Mateos Vicente, Beatriz; Romero-Zerbo, Silvana Y; Rodriguez-Rodriguez, Noé; Bellini, María José; Rodriguez de Fonseca, Fernando; Bermudez-Silva, Francisco Javier; Azcoitia, Iñigo; Garcia-Segura, Luis M; Viveros, María-Paz

    2011-09-01

    The neuroactive steroid estradiol reduces reactive astroglia after brain injury by mechanisms similar to those involved in the regulation of reactive gliosis by endocannabinoids. In this study, we have explored whether cannabinoid receptors are involved in the effects of estradiol on reactive astroglia. To test this hypothesis, the effects of estradiol, the cannabinoid CB1 antagonist/inverse agonist AM251, and the cannabinoid CB2 antagonist/inverse agonist AM630 were assessed in the cerebral cortex of male rats after a stab wound brain injury. Estradiol reduced the number of vimentin immunoreactive astrocytes and the number of glial fibrillary acidic protein immunoreactive astrocytes in the proximity of the wound. The effect of estradiol was significantly inhibited by the administration of either CB1 or CB2 receptor antagonists. The effect of estradiol may be in part mediated by alterations in endocannabinoid signaling because the hormone increased in the injured cerebral cortex the messenger RNA levels of CB2 receptors and of some of the enzymes involved in the synthesis and metabolism of endocannabinoids. These findings suggest that estradiol may decrease reactive astroglia in the injured brain by regulating the activity of the endocannabinoid system.

  15. Cannabinoid Receptors CB1 and CB2 Modulate the Electroretinographic Waves in Vervet Monkeys

    PubMed Central

    Bouskila, Joseph; Harrar, Vanessa; Javadi, Pasha; Beierschmitt, Amy; Palmour, Roberta; Casanova, Christian; Bouchard, Jean-François; Ptito, Maurice

    2016-01-01

    The expression patterns of the cannabinoid receptor type 1 (CB1R) and the cannabinoid receptor type 2 (CB2R) are well documented in rodents and primates. In vervet monkeys, CB1R is present in the retinal neurons (photoreceptors, horizontal cells, bipolar cells, amacrine cells, and ganglion cells) and CB2R is exclusively found in the retinal glia (Müller cells). However, the role of these cannabinoid receptors in normal primate retinal function remains elusive. Using full-field electroretinography in adult vervet monkeys, we recorded changes in neural activity following the blockade of CB1R and CB2R by the intravitreal administration of their antagonists (AM251 and AM630, resp.) in photopic and scotopic conditions. Our results show that AM251 increases the photopic a-wave amplitude at high flash intensities, whereas AM630 increases the amplitude of both the photopic a- and b-waves. In scotopic conditions, both blockers increased the b-wave amplitude but did not change the a-wave amplitude. These findings suggest an important role of CB1R and CB2R in primate retinal function. PMID:27069692

  16. Allosteric Modulation: An Alternate Approach Targeting the Cannabinoid CB1 Receptor.

    PubMed

    Nguyen, Thuy; Li, Jun-Xu; Thomas, Brian F; Wiley, Jenny L; Kenakin, Terry P; Zhang, Yanan

    2016-11-23

    The cannabinoid CB1 receptor is a G protein coupled receptor and plays an important role in many biological processes and physiological functions. A variety of CB1 receptor agonists and antagonists, including endocannabinoids, phytocannabinoids, and synthetic cannabinoids, have been discovered or developed over the past 20 years. In 2005, it was discovered that the CB1 receptor contains allosteric site(s) that can be recognized by small molecules or allosteric modulators. A number of CB1 receptor allosteric modulators, both positive and negative, have since been reported and importantly, they display pharmacological characteristics that are distinct from those of orthosteric agonists and antagonists. Given the psychoactive effects commonly associated with CB1 receptor agonists and antagonists/inverse agonists, allosteric modulation may offer an alternate approach to attain potential therapeutic benefits while avoiding inherent side effects of orthosteric ligands. This review details the complex pharmacological profiles of these allosteric modulators, their structure-activity relationships, and efforts in elucidating binding modes and mechanisms of actions of reported CB1 allosteric modulators. The ultimate development of CB1 receptor allosteric ligands could potentially lead to improved therapies for CB1-mediated neurological disorders.

  17. Delta(9)-Tetrahydrocannabinol enhances MCF-7 cell proliferation via cannabinoid receptor-independent signaling.

    PubMed

    Takeda, Shuso; Yamaori, Satoshi; Motoya, Erina; Matsunaga, Tamihide; Kimura, Toshiyuki; Yamamoto, Ikuo; Watanabe, Kazuhito

    2008-03-12

    We recently reported that Delta(9)-tetrahydrocannabinol (Delta(9)-THC) has the ability to stimulate the proliferation of human breast carcinoma MCF-7 cells. However, the mechanism of action remains to be clarified. The present study focused on the relationship between receptor expression and the effects of Delta(9)-THC on cell proliferation. RT-PCR analysis demonstrated that there was no detectable expression of CB receptors in MCF-7 cells. In accordance with this, no effects of cannabinoid 1/2 (CB1/2) receptor antagonists and pertussis toxin on cell proliferation were observed. Although MCF-7 cell proliferation is suggested to be suppressed by Delta(9)-THC in the presence of CB receptors, it was revealed that Delta(9)-THC could exert upregulation of living cells in the absence of the receptors. Interestingly, Delta(9)-THC upregulated human epithelial growth factor receptor type 2 (HER2) expression, which is known to be a predictive factor of human breast cancer and is able to stimulate cancer cells as well as MCF-7 cells. Actinomycin D-treatment interfered with the upregulation of HER2 and cell proliferation by cannabinoid. Taken together, these studies suggest that, in the absence of CB receptors, Delta(9)-THC can stimulate the proliferation of MCF-7 cells by modulating, at least in part, HER2 transcription.

  18. Striatal adenosine-cannabinoid receptor interactions in rats over-expressing adenosine A2A receptors.

    PubMed

    Chiodi, Valentina; Ferrante, Antonella; Ferraro, Luca; Potenza, Rosa Luisa; Armida, Monica; Beggiato, Sarah; Pèzzola, Antonella; Bader, Michael; Fuxe, Kjell; Popoli, Patrizia; Domenici, Maria Rosaria

    2016-03-01

    Adenosine A2A receptors (A2 A Rs) and cannabinoid CB1 receptors (CB1 Rs) are highly expressed in the striatum, where they functionally interact and form A2A /CB1 heteroreceptor complexes. We investigated the effects of CB1 R stimulation in a transgenic rat strain over-expressing A2 A Rs under the control of the neural-specific enolase promoter (NSEA2A rats) and in age-matched wild-type (WT) animals. The effects of the CB1 R agonist WIN 55,212-2 (WIN) were significantly lower in NSEA2A rats than in WT animals, as demonstrated by i) electrophysiological recordings of synaptic transmission in corticostriatal slices; ii) the measurement of glutamate outflow from striatal synaptosomes and iii) in vivo experiments on locomotor activity. Moreover, while the effects of WIN were modulated by both A2 A R agonist (CGS 21680) and antagonists (ZM 241385, KW-6002 and SCH-442416) in WT animals, the A2 A R antagonists failed to influence WIN-mediated effects in NSEA2A rats. The present results demonstrate that in rats with genetic neuronal over-expression of A2 A Rs, the effects mediated by CB1 R activation in the striatum are significantly reduced, suggesting a change in the stoichiometry of A2A and CB1 receptors and providing a strategy to dissect the involvement of A2 A R forming or not forming heteromers in the modulation of striatal functions. These findings add additional evidence for the existence of an interaction between striatal A2 A Rs and CB1 Rs, playing a fundamental role in the regulation of striatal functions. We studied A2A -CB1 receptor interaction in transgenic rats over-expressing adenosine A2A receptors under the control of the neuron-specific enolase promoter (NSEA2A ). In these rats, we demonstrated a reduced effect of the CB1 receptor agonist WIN 55,212-2 in the modulation of corticostriatal synaptic transmission and locomotor activity, while CB1 receptor expression level did not change with respect to WT rats. A reduction in the expression of A2A -CB1

  19. Dissecting striatal adenosine-cannabinoid receptor interactions. New clues from rats over-expressing adenosine A2A receptors.

    PubMed

    Ferré, Sergi; Sebastião, Ana Maria

    2016-03-01

    This Editorial highlights a study by Chiodi et al. () showing that the effects mediated by cannabinoid CB1 receptor (CB1R) activation in the striatum are significantly reduced in rats with neuronal over-expression of adenosine A2A receptors (A2AR). Two hypotheses are derived from that study. Hypothesis A: two subpopulations of pre-synaptic CB1R in corticostriatal glutamatergic terminals exist, one forming and another not forming heteromers with A2AR. Hypothesis B: CB1R are predominantly forming heteromers with A2AR. In the case of hypothesis A, the A2AR might be required for CB1R-A2AR heteromeric signaling, whereas non-heteromeric CB1R activity is inhibited by A2ARs. In the case of hypothesis B, up-regulation of A2ARs may perturb heteromeric stoichiometry, thus reducing CB1R functioning. In any case, pre-synaptic striatal A2AR-CB1R heteromers emerge as important targets of the effects of cannabinoids demonstrated at the neuronal and behavioral level. Read the highlighted article 'Striatal adenosine-cannabinoid receptor interactions in rats over-expressing adenosine A2A receptors' on page 907.

  20. Δ9-Tetrahydrocannabinol attenuates allogeneic host-versus-graft response and delays skin graft rejection through activation of cannabinoid receptor 1 and induction of myeloid-derived suppressor cells

    PubMed Central

    Sido, Jessica M.; Nagarkatti, Prakash S.; Nagarkatti, Mitzi

    2015-01-01

    Immune cells have been shown to express cannabinoid receptors and to produce endogenous ligands. Moreover, activation of cannabinoid receptors on immune cells has been shown to trigger potent immunosuppression. Despite such studies, the role of cannabinoids in transplantation, specifically to prevent allograft rejection, has not, to our knowledge, been investigated previously. In the current study, we tested the effect of THC on the suppression of HvGD as well as rejection of skin allografts. To this end, we studied HvGD by injecting H-2k splenocytes into H-2b mice and analyzing the immune response in the draining ingLNs. THC treatment significantly reduced T cell proliferation and activation in draining LNs of the recipient mice and decreased early stage rejection-indicator cytokines, including IL-2 and IFN-γ. THC treatment also increased the allogeneic skin graft survival. THC treatment in HvGD mice led to induction of MDSCs. Using MDSC depletion studies as well as adoptive transfer experiments, we found that THC-induced MDSCs were necessary for attenuation of HvGD. Additionally, using pharmacological inhibitors of CB1 and CB2 receptors and CB1 and CB2 knockout mice, we found that THC was working preferentially through CB1. Together, our research shows, for the first time to our knowledge, that targeting cannabinoid receptors may provide a novel treatment modality to attenuate HvGD and prevent allograft rejection. PMID:26034207

  1. Δ⁹-Tetrahydrocannabinol attenuates allogeneic host-versus-graft response and delays skin graft rejection through activation of cannabinoid receptor 1 and induction of myeloid-derived suppressor cells.

    PubMed

    Sido, Jessica M; Nagarkatti, Prakash S; Nagarkatti, Mitzi

    2015-09-01

    Immune cells have been shown to express cannabinoid receptors and to produce endogenous ligands. Moreover, activation of cannabinoid receptors on immune cells has been shown to trigger potent immunosuppression. Despite such studies, the role of cannabinoids in transplantation, specifically to prevent allograft rejection, has not, to our knowledge, been investigated previously. In the current study, we tested the effect of THC on the suppression of HvGD as well as rejection of skin allografts. To this end, we studied HvGD by injecting H-2(k) splenocytes into H-2(b) mice and analyzing the immune response in the draining ingLNs. THC treatment significantly reduced T cell proliferation and activation in draining LNs of the recipient mice and decreased early stage rejection-indicator cytokines, including IL-2 and IFN-γ. THC treatment also increased the allogeneic skin graft survival. THC treatment in HvGD mice led to induction of MDSCs. Using MDSC depletion studies as well as adoptive transfer experiments, we found that THC-induced MDSCs were necessary for attenuation of HvGD. Additionally, using pharmacological inhibitors of CB1 and CB2 receptors and CB1 and CB2 knockout mice, we found that THC was working preferentially through CB1. Together, our research shows, for the first time to our knowledge, that targeting cannabinoid receptors may provide a novel treatment modality to attenuate HvGD and prevent allograft rejection.

  2. Cannabinoids inhibit T-cells via cannabinoid receptor 2 in an in vitro assay for graft rejection, the mixed lymphocyte reaction.

    PubMed

    Robinson, Rebecca Hartzell; Meissler, Joseph J; Breslow-Deckman, Jessica M; Gaughan, John; Adler, Martin W; Eisenstein, Toby K

    2013-12-01

    Cannabinoids are known to have anti-inflammatory and immunomodulatory properties. Cannabinoid receptor 2 (CB2) is expressed mainly on leukocytes and is the receptor implicated in mediating many of the effects of cannabinoids on immune processes. This study tested the capacity of Δ(9)-tetrahydrocannabinol (Δ(9)-THC) and of two CB2-selective agonists to inhibit the murine Mixed Lymphocyte Reaction (MLR), an in vitro correlate of graft rejection following skin and organ transplantation. Both CB2-selective agonists and Δ(9)-THC significantly suppressed the MLR in a dose dependent fashion. The inhibition was via CB2, as suppression could be blocked by pretreatment with a CB2-selective antagonist, but not by a CB1 antagonist, and none of the compounds suppressed the MLR when splenocytes from CB2 deficient mice were used. The CB2 agonists were shown to act directly on T-cells, as exposure of CD3(+) cells to these compounds completely inhibited their action in a reconstituted MLR. Further, the CB2-selective agonists completely inhibited proliferation of purified T-cells activated by anti-CD3 and anti-CD28 antibodies. T-cell function was decreased by the CB2 agonists, as an ELISA of MLR culture supernatants revealed IL-2 release was significantly decreased in the cannabinoid treated cells. Together, these data support the potential of this class of compounds as useful therapies to prolong graft survival in transplant patients.

  3. Cannabinoids Inhibit T-cells via Cannabinoid Receptor 2 in an in vitro Assay for Graft Rejection, the Mixed Lymphocyte Reaction

    PubMed Central

    Robinson, Rebecca Hartzell; Meissler, Joseph J.; Breslow-Deckman, Jessica M.; Gaughan, John; Adler, Martin W.; Eisenstein, Toby K.

    2013-01-01

    Cannabinoids are known to have anti-inflammatory and immunomodulatory properties. Cannabinoid receptor 2 (CB2) is expressed mainly on leukocytes and is the receptor implicated in mediating many of the effects of cannabinoids on immune processes. This study tested the capacity of Δ9-tetrahydrocannabinol (Δ9-THC) and of two CB2-selective agonists to inhibit the murine Mixed Lymphocyte Reaction (MLR), an in vitro correlate of graft rejection following skin and organ transplantation. Both CB2-selective agonists and Δ9-THC significantly suppressed the MLR in a dose dependent fashion. The inhibition was via CB2, as suppression could be blocked by pretreatment with a CB2-selective antagonist, but not by a CB1 antagonist, and none of the compounds suppressed the MLR when splenocytes from CB2 deficient mice were used. The CB2 agonists were shown to act directly on T-cells, as exposure of CD3+ cells to these compounds completely inhibited their action in a reconstituted MLR. Further, the CB2-selective agonists completely inhibited proliferation of purified T-cells activated by anti-CD3 and anti-CD28 antibodies. T-cell function was decreased by the CB2 agonists, as an ELISA of MLR culture supernatants revealed IL-2 release was significantly decreased in the cannabinoid treated cells. Together, these data support the potential of this class of compounds as useful therapies to prolong graft survival in transplant patients. PMID:23824763

  4. Cannabis sativa and the endogenous cannabinoid system: therapeutic potential for appetite regulation.

    PubMed

    Farrimond, Jonathan A; Mercier, Marion S; Whalley, Benjamin J; Williams, Claire M

    2011-02-01

    The herb Cannabis sativa (C. sativa) has been used in China and on the Indian subcontinent for thousands of years as a medicine. However, since it was brought to the UK and then the rest of the western world in the late 19th century, its use has been a source of controversy. Indeed, its psychotropic side effects are well reported but only relatively recently has scientific endeavour begun to find valuable uses for either the whole plant or its individual components. Here, we discuss evidence describing the endocannabinoid system, its endogenous and exogenous ligands and their varied effects on feeding cycles and meal patterns. Furthermore we also critically consider the mounting evidence which suggests non-Δ(9) tetrahydrocannabinol phytocannabinoids play a vital role in C. sativa-induced feeding pattern changes. Indeed, given the wide range of phytocannabinoids present in C. sativa and their equally wide range of intra-, inter- and extra-cellular mechanisms of action, we demonstrate that non-Δ(9) tetrahydrocannabinol phytocannabinoids retain an important and, as yet, untapped clinical potential.

  5. Cannabis, cannabinoids and reproduction.

    PubMed

    Park, Boram; McPartland, John M; Glass, Michelle

    2004-02-01

    In most countries Cannabis is the most widely used illegal drug. Its use during pregnancy in developed nations is estimated to be approximately 10%. Recent evidence suggests that the endogenous cannabinoid system, now consisting of two receptors and multiple endocannabinoid ligands, may also play an important role in the maintenance and regulation of early pregnancy and fertility. The purpose of this review is therefore twofold, to examine the impact that cannabis use may have on fertility and reproduction, and to review the potential role of the endocannabinoid system in hormonal regulation, embryo implantation and maintenance of pregnancy.

  6. The novel endogenous cannabinoid 2-arachidonoylglycerol is inactivated by neuronal- and basophil-like cells: connections with anandamide.

    PubMed Central

    Di Marzo, V; Bisogno, T; Sugiura, T; Melck, D; De Petrocellis, L

    1998-01-01

    The novel endogenous cannabinoid 2-arachidonoylglycerol (2-AG) was rapidly inactivated by intact rat basophilic leukaemia (RBL-2H3) and mouse neuroblastoma (N18TG2) cells through diffusion/hydrolysis/reacylation processes. The hydrolysis of 2-AG was inhibited by typical esterase inhibitors and by more specific blockers of 'fatty acid amide hydrolase' (FAAH), the enzyme catalysing the hydrolysis of the other 'endocannabinoid', anandamide (AEA). No evidence for a facilitated-diffusion process was found. A 2-AG-hydrolysing activity was detected in homogenates from both cell lines, with the highest levels in membrane fractions. It exhibited an optimal pH at 10, and recognized both 2- and 1(3)- isomers of monoarachidonoylglycerol with similar efficiencies. The apparent Km and Vmax values for -3H-2-AG hydrolysis were 91 microM and 29 microM and 2.4 and 1.8 nmol.min-1.mg of protein-1 respectively in N18TG2 and RBL-2H3 cells. [3H]2-AG hydrolysis was inhibited by Cu2+, Zn2+ and p-hydroxymercuribenzoate, and by 2- or 1(3)-monolinoleoyl- and -linolenoyl-glycerols, but not by the oleoyl, palmitoyl and myristoyl congeners. Purified fractions from solubilized membrane proteins catalysed, at pH 9.5, the hydrolysis of 2-AG as well as AEA. Accordingly, AEA as well as FAAH inhibitors, including arachidonoyltrifluoromethyl ketone (ATFMK), blocked [3H]2-AG hydrolysis by N18TG2 and RBL-2H3 membranes, whereas 2-AG inhibited [14C]AEA hydrolysis. FAAH blockade by ATFMK preserved from inactivation the 2-AG synthesized de novo by intact N18TG2 cells stimulated with ionomycin. These data suggest that FAAH may be one of the enzymes deputed to the physiological inactivation of 2-AG, and create intriguing possibilities for the cross-regulation of 2-AG and AEA levels. PMID:9512456

  7. Antibody testing for brain immunohistochemistry: brain immunolabeling for the cannabinoid CB₂ receptor.

    PubMed

    Baek, Jean-Ha; Darlington, Cynthia L; Smith, Paul F; Ashton, John C

    2013-06-15

    The question of whether cannabinoid CB₂ receptors are expressed on neurons in the brain and under what circumstances they are expressed is controversial in cannabinoid neuropharmacology. While some studies have reported that CB₂ receptors are not detectable on neurons under normal circumstances, other studies have reported abundant neuronal expression. One reason for these apparent discrepancies is the reliance on incompletely validated CB₂ receptor antibodies and immunohistochemical procedures. In this study, we demonstrate some of the methodological problems encountered using three different commercial CB₂ receptor antibodies. We show that (1) the commonly used antibodies that were confirmed by many of the tests used for antibody validation still failed when examined using the knockout control test; (2) the coherence between the labeling patterns provided by two antibodies for the same protein at different epitopes may be misleading and must be validated using both low- and high-magnification microscopy; and (3) although CB₂ receptor antibodies may label neurons in the brain, the protein that the antibodies are labeling is not necessarily CB₂. These results showed that great caution needs to be exercised when interpreting the results of brain immunohistochemistry using CB₂ receptor antibodies and that, in general, none of the tests for antibody validity that have been proposed, apart from the knockout control test, are reliable.

  8. Effects of cannabinoid and vanilloid receptor agonists and their interaction on learning and memory in rats.

    PubMed

    Shiri, Mariam; Komaki, Alireza; Oryan, Shahrbanoo; Taheri, Masoumeh; Komaki, Hamidreza; Etaee, Farshid

    2017-04-01

    Despite previous findings on the effects of cannabinoid and vanilloid systems on learning and memory, the effects of the combined stimulation of these 2 systems on learning and memory have not been studied. Therefore, in this study, we tested the interactive effects of cannabinoid and vanilloid systems on learning and memory in rats by using passive avoidance learning (PAL) tests. Forty male Wistar rats were divided into the following 4 groups: (1) control (DMSO+saline), (2) WIN55,212-2, (3) capsaicin, and (4) WIN55,212-2 + capsaicin. On test day, capsaicin, a vanilloid receptor type 1 (TRPV1) agonist, or WIN55,212-2, a cannabinoid receptor (CB1/CB2) agonist, or both substances were injected intraperitoneally. Compared to the control group, the group treated with capsaicin (TRPV1 agonist) had better scores in the PAL acquisition and retention test, whereas treatment with WIN55,212-2 (CB1/CB2 agonist) decreased the test scores. Capsaicin partly reduced the effects of WIN55,212-2 on PAL and memory. We conclude that the acute administration of a TRPV1 agonist improves the rats' cognitive performance in PAL tasks and that a vanilloid-related mechanism may underlie the agonistic effect of WIN55,212-2 on learning and memory.

  9. Cannabinoid receptor 1 ligands revisited: Pharmacological assessment in the ACTOne system.

    PubMed

    Presley, Chaela S; Abidi, Ammaar H; Moore, Bob M

    2016-04-01

    In vitro cannabinoid pharmacology has evolved over time from simple receptor binding to include [(35)S]GTPγ, β-arrestin, and cAMP assays. Each assay has benefits and drawbacks; however, no single functional system has been used for high-throughput evaluation of compounds from binding to pharmacological functionality and antagonist assessment in a well-characterized human cell line. In this study, we evaluated and validated one system-ACTOne human embryonic kidney cells transfected with a cyclic nucleotide gated channel and cannabinoid receptor 1 (CB1)-and compared human CB1 affinity, functional, and antagonistic effects on cAMP with previously published results. The study was conducted on a diverse group of CB1 ligands, including endocannabinoids and related compounds, 2-AG, AEA, MAEA, and ACEA, the phytocannabinoid Δ(9) THC, and synthetic cannabinoids CP 55,940, WIN 55,212-2, SR 141716A, CP 945,598, and WIN 55,212-3. Our results were compared with literature values where human CB1 was used for affinity determination and cAMP was used as a functional readout. Here we report the first detailed evaluation of the ACTOne assay for the pharmacological evaluation of CB1 ligands. The results from the study reveal some interesting deviations from previously reported functional activities of the aforementioned ligands.

  10. Cannabinoid CB2 receptors are involved in the regulation of fibrogenesis during skin wound repair in mice

    PubMed Central

    LI, SHAN-SHAN; WANG, LIN-LIN; LIU, MIN; JIANG, SHU-KUN; ZHANG, MIAO; TIAN, ZHI-LING; WANG, MENG; LI, JIAO-YONG; ZHAO, RUI; GUAN, DA-WEI

    2016-01-01

    Studies have shown that cannabinoid CB2 receptors are involved in wound repair, however, its physiological roles in fibrogenesis remain to be elucidated. In the present study, the capacity of cannabinoid CB2 receptors in the regulation of skin fibrogenesis during skin wound healing was investigated. To assess the function of cannabinoid CB2 receptors, skin excisional BALB/c mice were treated either the cannabinoid CB2 receptor selective agonist, GP1a, or antagonist, AM630. Skin fibrosis was assessed by histological analysis and profibrotic cytokines were determined by immunohistochemistry, immunofluorescence staining, reverse transcription-quantitative polymerase chain reaction and immunoblotting in these animals. GP1a decreased collagen deposition, reduced the levels of transforming growth factor (TGF)-β1, TGF-β receptor I (TβRI) and phosphorylated small mothers against decapentaplegic homolog 3 (P-Smad3), but elevated the expression of its inhibitor, Smad7. By contrast, AM630 increased collagen deposition and the expression levels of TGF-β1, TβRI and P-Smad3. These results indicated that cannabinoid CB2 receptors modulate fibrogenesis and the TGF-β/Smad profibrotic signaling pathway during skin wound repair in the mouse. PMID:26935001

  11. delta9-Tetrahydrocannabinol excites rat VTA dopamine neurons through activation of cannabinoid CB1 but not opioid receptors.

    PubMed

    French, E D

    1997-05-02

    Behavioral, biochemical and recent electrophysiological data have increasingly implicated the involvement of dopamine in the central actions of cannabinoid compounds. However, the site and mechanism by which cannabinoids stimulate dopamine systems has been somewhat controversial. Central opioid systems have also been suggested to play a role in some cannabinoid-induced behaviors as evidenced by their attenuation in the presence of the opioid antagonist naloxone. However, recent studies using the cannabinoid receptor-selective antagonist SR141716A suggest that the central actions of psychoactive cannabinoids are mediated principally through activation of CB1 receptors. Using single cell electrophysiological recordings in the rat we assessed the effects of both SR141716A and naloxone on delta9-tetrahydrocannabinol (THC)-induced activation of ventral tegmental dopamine neurons. While dopamine cell firing was dose-dependently increased following cumulative dosing with delta9-THC it was partially or completely inhibited following pretreatment with 0.5 and 2 mg/kg SR141716A, respectively. However, 1 and 10 mg/kg naloxone failed to alter the response to delta9-THC. These data provide the first evidence that delta9-THC-induced changes in mesolimbic dopamine neuronal activity are mediated by the CB1 cannabinoid receptor, but a causal link for the involvement of opioid systems could not be established.

  12. Cannabinoid CB2 receptors in the gastrointestinal tract: a regulatory system in states of inflammation.

    PubMed

    Wright, K L; Duncan, M; Sharkey, K A

    2008-01-01

    The emerging potential for the cannabinoid (CB) system in modulating gastrointestinal inflammation has gained momentum over the last few years. Traditional and anecdotal use of marijuana for gastrointestinal disorders, such as diarrhoea and abdominal cramps is recognized, but the therapeutic benefit of cannabinoids in the 21st century is overshadowed by the psychoactive problems associated with CB1 receptor activation. However, the presence and function of the CB2 receptor in the GI tract, whilst not yet well characterized, holds great promise due to its immunomodulatory roles in inflammatory systems and its lack of psychotropic effects. This review of our current knowledge of CB2 receptors in the gastrointestinal tract highlights its role in regulating abnormal motility, modulating intestinal inflammation and limiting visceral sensitivity and pain. CB2 receptors represent a braking system and a pathophysiological mechanism for the resolution of inflammation and many of its symptoms. CB2 receptor activation therefore represents a very promising therapeutic target in gastrointestinal inflammatory states where there is immune activation and motility dysfunction.

  13. Modeling, Molecular Dynamics Simulation, and Mutation Validation for Structure of Cannabinoid Receptor 2 Based on Known Crystal Structures of GPCRs

    PubMed Central

    2015-01-01

    The cannabinoid receptor 2 (CB2) plays an important role in the immune system. Although a few of GPCRs crystallographic structures have been reported, it is still challenging to obtain functional transmembrane proteins and high resolution X-ray crystal structures, such as for the CB2 receptor. In the present work, we used 10 reported crystal structures of GPCRs which had high sequence identities with CB2 to construct homology-based comparative CB2 models. We applied these 10 models to perform a prescreen by using a training set consisting of 20 CB2 active compounds and 980 compounds randomly selected from the National Cancer Institute (NCI) database. We then utilized the known 170 cannabinoid receptor 1 (CB1) or CB2 selective compounds for further validation. Based on the docking results, we selected one CB2 model (constructed by β1AR) that was most consistent with the known experimental data, revealing that the defined binding pocket in our CB2 model was well-correlated with the training and testing data studies. Importantly, we identified a potential allosteric binding pocket adjacent to the orthosteric ligand-binding site, which is similar to the reported allosteric pocket for sodium ion Na+ in the A2AAR and the δ-opioid receptor. Our studies in correlation of our data with others suggested that sodium may reduce the binding affinities of endogenous agonists or its analogs to CB2. We performed a series of docking studies to compare the important residues in the binding pockets of CB2 with CB1, including antagonist, agonist, and our CB2 neutral compound (neutral antagonist) XIE35-1001. Then, we carried out 50 ns molecular dynamics (MD) simulations for the CB2 docked with SR144528 and CP55940, respectively. We found that the conformational changes of CB2 upon antagonist/agonist binding were congruent with recent reports of those for other GPCRs. Based on these results, we further examined one known residue, Val1133.32, and predicted two new residues, Phe183 in

  14. Celastrol attenuates inflammatory and neuropathic pain mediated by cannabinoid receptor type 2.

    PubMed

    Yang, Longhe; Li, Yanting; Ren, Jie; Zhu, Chenggang; Fu, Jin; Lin, Donghai; Qiu, Yan

    2014-08-06

    Celastrol, a major active ingredient of Chinese herb Tripterygium wilfordii Hook. f. (thunder god vine), has exhibited a broad spectrum of pharmacological activities, including anti-inflammation, anti-cancer and immunosuppression. In the present study, we used animal models of inflammatory pain and neuropathic pain, generated by carrageenan injection and spared nerve injury (SNI), respectively, to evaluate the effect of celastrol and to address the mechanisms underlying pain processing. Intraperitoneal (i.p.) injection of celastrol produced a dose-dependent inhibition of carrageenan-induced edema and allodynia. Real-time PCR analysis showed that celastrol (0.3 mg/kg, i.p.) significantly reduced mRNA expressions of inflammatory cytokines, TNF-α, IL-6, IL-1β, in carrageenan-injected mice. In SNI mice, pain behavior studies showed that celastrol (1 mg/kg, i.p.) effectively prevented the hypersensitivity of mechanical nociceptive response on the third day post-surgery and the seventh day post-surgery. Furthermore, the anti-hyperalgesic effects of celastrol in carrageenan-injected mice and SNI mice were reversed by SR144528 (1 mg/kg, i.p.), a specific cannabinoid receptor-2 (CB2) receptor antagonist, but not by SR141716 (1 mg/kg, i.p.), a specific cannabinoid receptor-1 (CB1) receptor antagonist. Taken together, our results demonstrate the analgesia effects of celastrol through CB2 signaling and propose the potential of exploiting celastrol as a novel candidate for pain relief.

  15. Attenuation of cannabinoid-induced inhibition of medullary dorsal horn neurons by a kappa-opioid receptor antagonist.

    PubMed

    Okada-Ogawa, Akiko; Kurose, Masayuki; Meng, Ian D

    2010-11-04

    The kappa-opioid receptor (KOR) antagonist norbinaltorphimine (nor-BNI) attenuates behavioral antinociception produced by spinal administration of the cannabinoid receptor agonist delta-9-tetrahydorcannabinol (THC). The present study examined the ability of nor-BNI to prevent cannabinoid-induced inhibition of medullary dorsal horn (MDH) nociceptive neurons and antinociception produced by the cannabinoid agonist WIN 55,212-2 (WIN-2). Extracellular, single-unit recordings of lamina I and lamina V MDH neurons were performed in urethane anesthetized rats. Heat-evoked activity was measured before and after local brainstem application of nor-BNI or vehicle followed by WIN-2. In both lamina I and lamina V neurons, prior application of nor-BNI prevented the inhibition of heat-evoked activity by WIN-2. In separate experiments, the contribution of KOR to cannabinoid-induced increases in heat-evoked head withdrawal latencies was assessed in lightly urethane-anesthetized rats. Antinociception produced by intrathecal administration of WIN-2 and THC was attenuated by prior administration of nor-BNI. In contrast, antinociception produced by the cannabinoid CP55940 remained unaffected by prior administration of nor-BNI. These results indicate that cannabinoid inhibition of nociceptive reflexes produced by WIN-2 and THC may result from inhibition of dorsal horn neurons through a KOR-dependent mechanism.

  16. Attenuation of cannabinoid-induced inhibition of medullary dorsal horn neurons by a kappa-opioid receptor antagonist

    PubMed Central

    Okada-Ogawa, Akiko; Kurose, Masayuki; Meng, Ian D.

    2010-01-01

    The kappa-opioid receptor (KOR) antagonist norbinaltorphimine (nor-BNI) attenuates behavioral antinociception produced by spinal administration of the cannabinoid receptor agonist delta-9-tetrahydorcannabinol (THC). The present study examined the ability of nor-BNI to prevent cannabinoid-induced inhibition of medullary dorsal horn (MDH) nociceptive neurons and antinociception produced by the cannabinoid agonist WIN 55,212-2 (WIN-2). Extracellular, single unit recordings of lamina I and lamina V MDH neurons was performed in urethane anesthetized rats. Heat-evoked activity was measured before and after local brainstem application of nor-BNI or vehicle followed by WIN-2. In both lamina I and lamina V neurons, prior application of nor-BNI prevented the inhibition of heat-evoked activity by WIN-2. In separate experiments, the contribution of KOR to cannabinoid-induced increases in heat-evoked head withdrawal latencies was assessed in lightly urethane-anesthetized rats. Antinociception produced by intrathecal administration of WIN-2 and THC was attenuated by prior administration of nor-BNI. In contrast, antinociception produced by the cannabinoid CP55940 remained unaffected by prior administration of nor-BNI. These results indicate that cannabinoid inhibition of nociceptive reflexes produced by WIN-2 and THC may result from inhibition of dorsal horn neurons through a KOR-dependent mechanism. PMID:20807519

  17. Impact of Cannabis, Cannabinoids, and Endocannabinoids in the Lungs

    PubMed Central

    Turcotte, Caroline; Blanchet, Marie-Renée; Laviolette, Michel; Flamand, Nicolas

    2016-01-01

    Since the identification of cannabinoid receptors in the 1990s, a research field has been dedicated to exploring the role of the cannabinoid system in immunity and the inflammatory response in human tissues and animal models. Although the cannabinoid system is present and crucial in many human tissues, studying the impact of cannabinoids on the lungs is particularly relevant because of their contact with exogenous cannabinoids in the context of marijuana consumption. In the past two decades, the scientific community has gathered a large body of evidence supporting that the activation of the cannabinoid system alleviates pain and reduces inflammation. In the context of lung inflammation, exogenous and endogenous cannabinoids have shown therapeutic potential because of their inhibitory effects on immune cell recruitment and functions. On the other hand, cannabinoids were shown to be deleterious to lung function and to impact respiratory pathogen clearance. In this review, we present the existing data on the regulation of lung immunity and inflammation by phytocannabinoids, synthetic cannabinoids and endocannabinoids. PMID:27695418

  18. Interacting Cannabinoid and Opioid Receptors in the Nucleus Accumbens Core Control Adolescent Social Play

    PubMed Central

    Manduca, Antonia; Lassalle, Olivier; Sepers, Marja; Campolongo, Patrizia; Cuomo, Vincenzo; Marsicano, Giovanni; Kieffer, Brigitte; Vanderschuren, Louk J. M. J; Trezza, Viviana; Manzoni, Olivier J. J.

    2016-01-01

    Social play behavior is a highly rewarding, developmentally important form of social interaction in young mammals. However, its neurobiological underpinnings remain incompletely understood. Previous work has suggested that opioid and endocannabinoid neurotransmission interact in the modulation of social play. Therefore, we combined behavioral, pharmacological, electrophysiological, and genetic approaches to elucidate the role of the endocannabinoid 2-arachidonoylglycerol (2-AG) in social play, and how cannabinoid and opioid neurotransmission interact to control social behavior in adolescent rodents. Systemic administration of the 2-AG hydrolysis inhibitor JZL184 or the opioid receptor agonist morphine increased social play behavior in adolescent rats. These effects were blocked by systemic pretreatment with either CB1 cannabinoid receptor (CB1R) or mu-opioid receptor (MOR) antagonists. The social play-enhancing effects of systemic morphine or JZL184 treatment were also prevented by direct infusion of the CB1R antagonist SR141716 and the MOR antagonist naloxone into the nucleus accumbens core (NAcC). Searching for synaptic correlates of these effects in adolescent NAcC excitatory synapses, we observed that CB1R antagonism blocked the effect of the MOR agonist DAMGO and, conversely, that naloxone reduced the effect of a cannabinoid agonist. These results were recapitulated in mice, and completely abolished in CB1R and MOR knockout mice, suggesting that the functional interaction between CB1R and MOR in the NAcC in the modulation of social behavior is widespread in rodents. The data shed new light on the mechanism by which endocannabinoid lipids and opioid peptides interact to orchestrate rodent socioemotional behaviors. PMID:27899885

  19. Interacting Cannabinoid and Opioid Receptors in the Nucleus Accumbens Core Control Adolescent Social Play.

    PubMed

    Manduca, Antonia; Lassalle, Olivier; Sepers, Marja; Campolongo, Patrizia; Cuomo, Vincenzo; Marsicano, Giovanni; Kieffer, Brigitte; Vanderschuren, Louk J M J; Trezza, Viviana; Manzoni, Olivier J J

    2016-01-01

    Social play behavior is a highly rewarding, developmentally important form of social interaction in young mammals. However, its neurobiological underpinnings remain incompletely understood. Previous work has suggested that opioid and endocannabinoid neurotransmission interact in the modulation of social play. Therefore, we combined behavioral, pharmacological, electrophysiological, and genetic approaches to elucidate the role of the endocannabinoid 2-arachidonoylglycerol (2-AG) in social play, and how cannabinoid and opioid neurotransmission interact to control social behavior in adolescent rodents. Systemic administration of the 2-AG hydrolysis inhibitor JZL184 or the opioid receptor agonist morphine increased social play behavior in adolescent rats. These effects were blocked by systemic pretreatment with either CB1 cannabinoid receptor (CB1R) or mu-opioid receptor (MOR) antagonists. The social play-enhancing effects of systemic morphine or JZL184 treatment were also prevented by direct infusion of the CB1R antagonist SR141716 and the MOR antagonist naloxone into the nucleus accumbens core (NAcC). Searching for synaptic correlates of these effects in adolescent NAcC excitatory synapses, we observed that CB1R antagonism blocked the effect of the MOR agonist DAMGO and, conversely, that naloxone reduced the effect of a cannabinoid agonist. These results were recapitulated in mice, and completely abolished in CB1R and MOR knockout mice, suggesting that the functional interaction between CB1R and MOR in the NAcC in the modulation of social behavior is widespread in rodents. The data shed new light on the mechanism by which endocannabinoid lipids and opioid peptides interact to orchestrate rodent socioemotional behaviors.

  20. The actions of some cannabinoid receptor ligands in the rat isolated mesenteric artery

    PubMed Central

    White, Richard; Robin Hiley, C

    1998-01-01

    The actions of a number of cannabinoid receptor ligands were investigated using the myograph-mounted rat isolated mesenteric artery. Anandamide, CP 55,940, HU-210, palmitoylethanolamide and WIN 55,212-2 all caused concentration-dependent relaxations of methoxamine-precontracted vessels which were not affected by removal of the endothelium.Precontracting vessels with 60 mM KCl instead of methoxamine greatly reduced the vasorelaxant effects of anandamide and palmitoylethanolamide. High K+ solution caused a modest decrease in the relaxant potency of CP 55,940 and HU-210, and had no effect on relaxations induced by WIN 55,212-2.Relaxations of methoxamine-induced tone by anandamide, CP 55,940 and HU-210, but not palmitoylethanolamide and WIN 55,212-2, were attenuated by the cannabinoid receptor antagonist, SR 141716A. Relaxation of vessels contracted with 60 mM KCl by CP 55,940 was also sensitive to SR 141716A.Anandamide and CP 55,940 caused small but concentration-dependent contractions in resting vessels in the absence of extracellular calcium. These were not sensitive to SR 141716A. Palmitoylethanolamide and WIN 55,212-2 produced smaller contractions only at higher concentrations.Anandamide and CP 55,940, but not palmitoylethanolamide and WIN 55,212-2, caused concentration-dependent inhibition of the phasic contractions induced by methoxamine in calcium-free conditions, but only anandamide caused inhibition of contractions to caffeine under such conditions. These inhibitory effects were not antagonised by SR 141716A.The present study provides the first detailed investigation of the actions of cannabinoid agonists on vascular smooth muscle. Our results show that these compounds exert both receptor-dependent and -independent effects on agonist-induced calcium mobilization in the rat isolated mesenteric artery. PMID:9806337

  1. Expression, surface immobilization, and characterization of functional recombinant cannabinoid receptor CB2.

    PubMed

    Locatelli-Hoops, Silvia C; Gorshkova, Inna; Gawrisch, Klaus; Yeliseev, Alexei A

    2013-10-01

    Human peripheral cannabinoid receptor CB2, a G protein-coupled receptor (GPCR) involved in regulation of immune response has become an important target for pharmaceutical drug development. Structural and functional studies on CB2 may benefit from immobilization of the purified and functional receptor onto a suitable surface at a controlled density and, preferably in a uniform orientation. The goal of this project was to develop a generic strategy for preparation of functional recombinant CB2 and immobilization at solid interfaces. Expression of CB2 as a fusion with Rho-tag (peptide composed of the last nine amino acids of rhodopsin) in E. coli was evaluated in terms of protein levels, accessibility of the tag, and activity of the receptor. The structural integrity of CB2 was tested by ligand binding to the receptor solubilized in detergent micelles, captured on tag-specific monoclonal 1D4 antibody-coated resin. Highly pure and functional CB2 was obtained by sequential chromatography on a 1D4- and Ni-NTA-resin and its affinity to the 1D4 antibody characterized by surface plasmon resonance (SPR). Either the purified receptor or fusion CB2 from the crude cell extract was captured onto a 1D4-coated CM4 chip (Biacore) in a quantitative fashion at uniform orientation as demonstrated by the SPR signal. Furthermore, the accessibility of the extracellular surface of immobilized CB2 and the affinity of interaction with a novel monoclonal antibody NAA-1 was studied by SPR. In summary, we present an integral strategy for purification, surface immobilization, ligand- and antibody binding studies of functional cannabinoid receptor CB2.

  2. Opposing roles for cannabinoid receptor type-1 (CB₁) and transient receptor potential vanilloid type-1 channel (TRPV1) on the modulation of panic-like responses in rats.

    PubMed

    Casarotto, Plínio C; Terzian, Ana Luisa B; Aguiar, Daniele C; Zangrossi, Hélio; Guimarães, Francisco S; Wotjak, Carsten T; Moreira, Fabrício A

    2012-01-01

    The midbrain dorsal periaqueductal gray (dPAG) has an important role in orchestrating anxiety- and panic-related responses. Given the cellular and behavioral evidence suggesting opposite functions for cannabinoid type 1 receptor (CB₁) and transient receptor potential vanilloid type-1 channel (TRPV1), we hypothesized that they could differentially influence panic-like reactions induced by electrical stimulation of the dPAG. Drugs were injected locally and the expression of CB₁ and TRPV1 in this structure was assessed by immunofluorescence and confocal microscopy. The CB₁-selective agonist, ACEA (0.01, 0.05 and 0.5 pmol) increased the threshold for the induction of panic-like responses solely at the intermediary dose, an effect prevented by the CB₁-selective antagonist, AM251 (75 pmol). Panicolytic-like effects of ACEA at the higher dose were unmasked by pre-treatment with the TRPV1 antagonist capsazepine (0.1 nmol). Similarly to ACEA, capsazepine (1 and 10 nmol) raised the threshold for triggering panic-like reactions, an effect mimicked by another TRPV1 antagonist, SB366791 (1 nmol). Remarkably, the effects of both capsazepine and SB366791 were prevented by AM251 (75 pmol). These pharmacological data suggest that a common endogenous agonist may have opposite functions at a given synapse. Supporting this view, we observed that several neurons in the dPAG co-expressed CB₁ and TRPV1. Thus, the present work provides evidence that an endogenous substance, possibly anandamide, may exert both panicolytic and panicogenic effects via its actions at CB₁ receptors and TRPV1 channels, respectively. This tripartite set-point system might be exploited for the pharmacotherapy of panic attacks and anxiety-related disorders.

  3. Immunohistochemistry Detected and Localized Cannabinoid Receptor Type 2 in Bovine Fetal Pancreas at Late Gestation

    PubMed Central

    Dall’Aglio, Cecilia; Polisca, Angela; Cappai, Maria Grazia; Mercati, Francesca; Troisi, Alessandro; Pirino, Carolina; Scocco, Paola; Maranesi, Margherita

    2017-01-01

    At present, data on the endocannabinoid system expression and distribution in the pancreatic gland appear scarce and controversial as descriptions are limited to humans and laboratory animals. Since the bovine pancreas is very similar to the human in endocrine portion development and control, studies on the fetal gland could prove to be very interesting, as an abnormal maternal condition during late pregnancy may be a predisposing trigger for adult metabolic disorders. The present investigation studied cannabinoid receptor type 2 presence and distribution in the bovine fetal pancreas towards the end of gestation. Histological analyses revealed numerous endocrinal cell clusters or islets which were distributed among exocrine adenomeri in connectival tissue. Immunohistochemistry showed that endocrine-islets contained some CB2-positive cells with a very peculiar localization that is a few primarily localized at the edges of islets and some of them also scattered in the center of the cluster. Characteristically, also the epithelium of the excretory ducts and the smooth muscle layers of the smaller arteries, in the interlobular glandular septa, tested positive for the CB2 endocannabinoid receptor. Consequently, the endocannabinoid system, via the cannabinoid receptor type 2, was hypothesized to play a major role in controlling pancreas function from normal fetal development to correct metabolic functioning in adulthood. PMID:28348424

  4. CB1 cannabinoid receptor enrichment in the ependymal region of the adult human spinal cord

    PubMed Central

    Paniagua-Torija, Beatriz; Arevalo-Martin, Angel; Ferrer, Isidro; Molina-Holgado, Eduardo; Garcia-Ovejero, Daniel

    2015-01-01

    Cannabinoids are involved in the regulation of neural stem cell biology and their receptors are expressed in the neurogenic niches of adult rodents. In the spinal cord of rats and mice, neural stem cells can be found in the ependymal region, surrounding the central canal, but there is evidence that this region is largely different in adult humans: lacks a patent canal and presents perivascular pseudorosettes, typically found in low grade ependymomas. Using Laser Capture Microdissection, Taqman gene expression assays and immunohistochemistry, we have studied the expression of endocannabinoid system components (receptors and enzymes) at the human spinal cord ependymal region. We observe that ependymal region is enriched in CB1 cannabinoid receptor, due to high CB1 expression in GFAP+ astrocytic domains. However, in human spinal cord levels that retain central canal patency we found ependymal cells with high CB1 expression, equivalent to the CB1HIGH cell subpopulation described in rodents. Our results support the existence of ependymal CB1HIGH cells across species, and may encourage further studies on this subpopulation, although only in cases when central canal is patent. In the adult human ependyma, which usually shows central canal absence, CB1 may play a different role by modulating astrocyte functions. PMID:26634814

  5. CB1 cannabinoid receptor enrichment in the ependymal region of the adult human spinal cord.

    PubMed

    Paniagua-Torija, Beatriz; Arevalo-Martin, Angel; Ferrer, Isidro; Molina-Holgado, Eduardo; Garcia-Ovejero, Daniel

    2015-12-04

    Cannabinoids are involved in the regulation of neural stem cell biology and their receptors are expressed in the neurogenic niches of adult rodents. In the spinal cord of rats and mice, neural stem cells can be found in the ependymal region, surrounding the central canal, but there is evidence that this region is largely different in adult humans: lacks a patent canal and presents perivascular pseudorosettes, typically found in low grade ependymomas. Using Laser Capture Microdissection, Taqman gene expression assays and immunohistochemistry, we have studied the expression of endocannabinoid system components (receptors and enzymes) at the human spinal cord ependymal region. We observe that ependymal region is enriched in CB1 cannabinoid receptor, due to high CB1 expression in GFAP+ astrocytic domains. However, in human spinal cord levels that retain central canal patency we found ependymal cells with high CB1 expression, equivalent to the CB1(HIGH) cell subpopulation described in rodents. Our results support the existence of ependymal CB1(HIGH) cells across species, and may encourage further studies on this subpopulation, although only in cases when central canal is patent. In the adult human ependyma, which usually shows central canal absence, CB1 may play a different role by modulating astrocyte functions.

  6. Overactive cannabinoid 1 receptor in podocytes drives type 2 diabetic nephropathy.

    PubMed

    Jourdan, Tony; Szanda, Gergő; Rosenberg, Avi Z; Tam, Joseph; Earley, Brian James; Godlewski, Grzegorz; Cinar, Resat; Liu, Ziyi; Liu, Jie; Ju, Cynthia; Pacher, Pál; Kunos, George

    2014-12-16

    Diabetic nephropathy is a major cause of end-stage kidney disease, and overactivity of the endocannabinoid/cannabinoid 1 receptor (CB1R) system contributes to diabetes and its complications. Zucker diabetic fatty (ZDF) rats develop type 2 diabetic nephropathy with albuminuria, reduced glomerular filtration, activation of the renin-angiotensin system (RAS), oxidative/nitrative stress, podocyte loss, and increased CB1R expression in glomeruli. Peripheral CB1R blockade initiated in the prediabetic stage prevented these changes or reversed them when animals with fully developed diabetic nephropathy were treated. Treatment of diabetic ZDF rats with losartan, an angiotensin II receptor-1 (Agtr1) antagonist, attenuated the development of nephropathy and down-regulated renal cortical CB1R expression, without affecting the marked hyperglycemia. In cultured human podocytes, CB1R and desmin gene expression were increased and podocin and nephrin content were decreased by either the CB1R agonist arachydonoyl-2'-chloroethylamide, angiotensin II, or high glucose, and the effects of all three were antagonized by CB1R blockade or siRNA-mediated knockdown of CNR1 (the cannabinoid type 1 receptor gene). We conclude that increased CB1R signaling in podocytes contributes to the development of diabetic nephropathy and represents a common pathway through which both hyperglycemia and increased RAS activity exert their deleterious effects, highlighting the therapeutic potential of peripheral CB1R blockade.

  7. Structure-affinity relationships and pharmacological characterization of new alkyl-resorcinol cannabinoid receptor ligands: Identification of a dual cannabinoid receptor/TRPA1 channel agonist.

    PubMed

    Brizzi, Antonella; Aiello, Francesca; Marini, Pietro; Cascio, Maria Grazia; Corelli, Federico; Brizzi, Vittorio; De Petrocellis, Luciano; Ligresti, Alessia; Luongo, Livio; Lamponi, Stefania; Maione, Sabatino; Pertwee, Roger G; Di Marzo, Vincenzo

    2014-09-01

    In our ongoing program aimed at deeply investigating the endocannabinoid system (ES), a set of new alkyl-resorcinol derivatives was prepared focusing on the nature and the importance of the carboxamide functionality. Binding studies on CB1 and CB2 receptors, monoacylglycerol lipase (MAGL) and fatty acid amide hydrolase (FAAH) showed that some of the newly developed compounds behaved as very potent cannabinoid receptor ligands (Ki in the nanomolar range) while, however, none of them was able to inhibit MAGL and/or FAAH. Derivative 11 was a potent CB1 and CB2 ligand, with Ki values similar to WIN 55,212, exhibiting a CB1 and CB2 agonist profile in vitro. In the formalin test of peripheral acute and inflammatory pain in mice, this compound showed a weak and delayed antinociceptive effect against the second phase of the nocifensive response, exhibiting, interestingly, a quite potent transient receptor potential ankyrin type-1 (TRPA1) channel agonist activity. Moreover, derivative 14, characterized by lower affinity but higher CB2 selectivity than 11, proved to behave as a weak CB2 competitive inverse agonist.

  8. Oxidative stress and cannabinoid receptor expression in type-2 diabetic rat pancreas following treatment with Δ⁹-THC.

    PubMed

    Coskun, Zeynep Mine; Bolkent, Sema

    2014-10-01

    The objectives of study were (a) to determine alteration of feeding, glucose level and oxidative stress and (b) to investigate expression and localization of cannabinoid receptors in type-2 diabetic rat pancreas treated with Δ(9)-tetrahydrocannabinol (Δ(9)-THC). Rats were randomly divided into four groups: control, Δ(9)-THC, diabetes and diabetes + Δ(9)-THC groups. Diabetic rats were treated with a single dose of nicotinamide (85 mg/kg) 15 min before injection of streptozotocin (65 mg/kg). Δ(9)-THC was administered intraperitoneally at 3 mg/kg/day for 7 days. Body weights and blood glucose level of rats in all groups were measured on days 0, 7, 14 and 21. On day 15 after the Δ(9)-THC injections, pancreatic tissues were removed. Blood glucose levels and body weights of diabetic rats treated with Δ(9)-THC did not show statistically significant changes when compared with the diabetic animals on days 7, 14 and 21. Treatment with Δ(9)-THC significantly increased pancreas glutathione levels, enzyme activities of superoxide dismutase and catalase in diabetes compared with non-treatment diabetes group. The cannabinoid 1 receptor was found in islets, whereas the cannabinoid 2 receptor was found in pancreatic ducts. Their localization in cells was both nuclear and cytoplasmic. We can suggest that Δ(9) -THC may be an important agent for the treatment of oxidative damages induced by diabetes. However, it must be supported with anti-hyperglycaemic agents. Furthermore, the present study for the first time emphasizes that Δ(9)-THC may improve pancreatic cells via cannabinoid receptors in diabetes. The aim of present study was to elucidate the effects of Δ(9)-THC, a natural cannabinoid receptor agonist, on the expression and localization of cannabinoid receptors, and oxidative stress statue in type-2 diabetic rat pancreas. Results demonstrate that the cannabinoid receptors are presented in both Langerhans islets and duct regions. The curative effects

  9. A user’s guide to cannabinoid therapies in oncology

    PubMed Central

    Maida, V.; Daeninck, P.J.

    2016-01-01

    “Cannabinoid” is the collective term for a group of chemical compounds that either are derived from the Cannabis plant, are synthetic analogues, or occur endogenously. Although cannabinoids interact mostly at the level of the currently recognized cannabinoid receptors, they might have cross reactivity, such as at opioid receptors. Patients with malignant disease represent a cohort within health care that have some of the greatest unmet needs despite the availability of a plethora of guideline-driven disease-modulating treatments and pain and symptom management options. Cannabinoid therapies are varied and versatile, and can be offered as pharmaceuticals (nabilone, dronabinol, and nabiximols), dried botanical material, and edible organic oils infused with cannabis extracts. Cannabinoid therapy regimens can be creative, involving combinations of all of the aforementioned modalities. Patients with malignant disease, at all points of their disease trajectory, could be candidates for cannabinoid therapies whether as monotherapies or as adjuvants. The most studied and established roles for cannabinoid therapies include pain, chemotherapy-induced nausea and vomiting, and anorexia. Moreover, given their breadth of activity, cannabinoids could be used to concurrently optimize the management of multiple symptoms, thereby reducing overall polypharmacy. The use of cannabinoid therapies could be effective in improving quality of life and possibly modifying malignancy by virtue of direct effects and in improving compliance or adherence with disease-modulating treatments such as chemotherapy and radiation therapy. PMID:28050136

  10. Cannabis and cannabinoids: pharmacology and rationale for clinical use.

    PubMed

    Pertwee, R G

    1999-10-01

    It is now known that there are at least two types of cannabinoid receptors. These are CB1 receptors, present mainly on central and peripheral neurones, and CB2 receptors, present mainly on immune cells. Endogenous cannabinoid receptor agonists ('endocannabinoids') have also been identified. The discovery of this 'endogenous cannabinoid system' has led to the development of selective CB1 and CB2 receptor ligands and fueled renewed interest in the clinical potential of cannabinoids. Two cannabinoid CB1 receptor agonists are already used clinically, as antiemetics or as appetite stimulants. These are D 9 - tetrahydrocannabinol (THC) and nabilone. Other possible uses for CB1 receptor agonists include the suppression of muscle spasm/spasticity associated with multiple sclerosis or spinal cord injury, the relief of chronic pain and the management of glaucoma and bronchial asthma. CB1 receptor antagonists may also have clinical applications, e. g. as appetite suppressants and in the management of schizophrenia or disorders of cognition and memory. So too may CB2 receptor ligands and drugs that activate cannabinoid receptors indirectly by augmenting endocannabinoid levels at cannabinoid receptors. When taken orally, THC seems to undergo variable absorption and to have a narrow 'therapeutic window' (dose range in which it is effective without producing significant unwanted effects). This makes it difficult to predict an oral dose that will be both effective and tolerable to a patient and indicates a need for better cannabinoid formulations and modes of administration. For the therapeutic potential of cannabis or CB1 receptor agonists to be fully exploited, it will be important to establish objectively and conclusively (a) whether these agents have efficacy against selected symptoms that is of clinical significance and, if so, whether the benefits outweigh the risks, (b) whether cannabis has therapeutic advantages over individual cannabinoids, (c) whether there is a need for

  11. Receptor subtypes and signal transduction mechanisms contributing to the estrogenic attenuation of cannabinoid-induced changes in energy homeostasis

    PubMed Central

    Washburn, Neal; Borgquist, Amanda; Wang, Kate; Jeffery, Garrett S.; Kelly, Martin J.; Wagner, Edward J.

    2013-01-01

    We examined the receptor subtypes and signal transduction mechanisms contributing to the estrogenic modulation of cannabinoid-induced changes in energy balance. Food intake and, in some cases, O2 consumption, CO2 production and the respiratory exchange ratio, were evaluated in ovariectomized female guinea pigs treated s.c. with the cannabinoid receptor agonist WIN 55,212-2 or its cremephor/ethanol/0.9% saline vehicle, and either with estradiol benzoate (EB), the estrogen receptor (ER)α agonist PPT, the ERβ agonist DPN, the Gq-coupled membrane ER agonist STX, the GPR30 agonist G-1 or their respective vehicles. Patch-clamp recordings were performed in hypothalamic slices. EB, STX, PPT and G-1 decreased daily food intake. Of these, EB, STX and PPT blocked the WIN 55,212-2-induced increase in food intake within 1-4 hr. The estrogenic diminution of cannabinoid-induced hyperphagia correlated with a rapid (within 15 min) attenuation of cannabinoid-mediated decreases in glutamatergic synaptic input onto arcuate neurons, which was completely blocked by inhibition of protein kinase C (PKC) and attenuated by inhibition of protein kinase A (PKA). STX, but not PPT, mimicked this rapid estrogenic effect. However, PPT abolished the cannabinoid-induced inhibition of glutamatergic neurotransmission in cells from animals treated 24 hr prior. The estrogenic antagonism of this presynaptic inhibition was observed in anorexigenic POMC neurons. These data reveal that estrogens negatively modulate cannabinoid-induced changes in energy balance via Gq-coupled membrane ER- and ERα-mediated mechanisms involving activation of PKC and PKA. As such, they further our understanding of the pathways through which estrogens act to temper cannabinoid sensitivity in regulating energy homeostasis in females. PMID:22538462

  12. The anabolic steroid nandrolone alters cannabinoid self-administration and brain CB1 receptor density and function.

    PubMed

    Struik, Dicky; Fadda, Paola; Zara, Tamara; Zamberletti, Erica; Rubino, Tiziana; Parolaro, Daniela; Fratta, Walter; Fattore, Liana

    2017-01-01

    Clinical and pre-clinical observations indicate that anabolic-androgenic steroids can induce neurobiological changes that alter the rewarding effects of drugs of abuse. In this study, we investigated the effect of the anabolic steroid nandrolone on the rewarding properties of the cannabinoid CB1 receptor agonist WIN55,212-2 (WIN) in rats. Lister Hooded male rats were treated intramuscularly with nandrolone (15mg/kg) or vehicle for 14 consecutive days, and then allowed to self-administer WIN (12.5μg/kg/infusion) intravenously. After reaching stable drug intake, self-administration behavior was extinguished to examine drug- and cue-induced reinstatement of cannabinoid-seeking behavior. Other behavioral parameters presumed to influence drug-taking and drug-seeking behaviors were examined to gain more insight into the behavioral specificity of nandrolone treatment. Finally, animals were sacrificed for analysis of CB1 receptor density and function in selected brain areas. We found that nandrolone-treated rats self-administered up to 2 times more cannabinoid than vehicle-treated rats, but behaved similarly to control rats when tested for drug- and cue-induced reinstatement of cannabinoid-seeking behavior. Enhanced cannabinoid intake by nandrolone-treated rats was not accompanied by changes in locomotor activity, sensorimotor gating, or memory function. However, our molecular data show that after chronic WIN self-administration nandrolone-treated rats display altered CB1 receptor density and function in selected brain areas. We hypothesize that increased cannabinoid self-administration in nandrolone-treated rats results from a nandrolone-induced decrease in reward function, which rats seem to compensate by voluntarily increasing their cannabinoid intake. Altogether, our findings corroborate the hypothesis that chronic exposure to anabolic-androgenic steroids induces dysfunction of the reward pathway in rats and might represent a potential risk factor for abuse of

  13. Deficits in sensory-specific devaluation task performance following genetic deletions of cannabinoid (CB1) receptor.

    PubMed

    Crombag, Hans S; Johnson, Alexander W; Zimmer, Anne M; Zimmer, Andreas; Holland, Peter C

    2010-01-01

    Cannabinoid CB1 receptor is abundantly expressed throughout the CNS and is implicated in numerous physiological and behavioral functions, including appetite and feeding. In the present study, wild-type and CB1 heterozygous and homozygous knockout mice were tested on an instrumental outcome-selective devaluation task to assess changes in acquired instrumental response levels for a distinct food reward following selective satiation. Deletion of CB1 receptor, as well as reduction in CB1 expression (HET), produced deficits in outcome-selective instrumental devaluation. These results identify a critical role for CB1 receptor in the ability of animals to represent, update, and/or use sensory-specific outcome representations to alter appetitive behaviors.

  14. Conformational Restriction Leading to a Selective CB2 Cannabinoid Receptor Agonist Orally Active Against Colitis

    PubMed Central

    2014-01-01

    The CB2 cannabinoid receptor has been implicated in the regulation of intestinal inflammation. Following on from the promising activity of a series of 4-oxo-1,4-dihydroquinoline-3-carboxamide, we developed constrained analogues based on a 2H-pyrazolo[4,3-c]quinolin-3(5H)-one scaffold, with improved affinity for the hCB2 receptor and had very high selectivity over the hCB1 receptor. Importantly, the lead of this series (26, hCB2: Ki = 0.39 nM, hCB1: Ki > 3000 nM) was found to protect mice against experimental colitis after oral administration. PMID:25699149

  15. Upregulation of Cannabinoid Type 1 Receptors in Dopamine D2 Receptor Knockout Mice Is Reversed by Chronic Forced Ethanol Consumption

    SciTech Connect

    Thanos, P.K.; Wang, G.; Thanos, P.K.; Gopez, V.; Delis, F.; Michaelides, M.; Grand, D.K.; Wang, G.-J.; Kunos, G.; Volkow, N.D.

    2011-01-01

    The anatomical proximity of the cannabinoid type 1 (CNR1/CB1R) and the dopamine D2 receptors (DRD2), their ability to form CB1R-DRD2 heteromers, their opposing roles in locomotion, and their involvement in ethanol's reinforcing and addictive properties prompted us to study the levels and distribution of CB1R after chronic ethanol intake, in the presence and absence of DRD2. We monitored the drinking patterns and locomotor activity of Drd2+/+ and Drd2-/- mice consuming either water or a 20% (v/v) ethanol solution (forced ethanol intake) for 6 months and used the selective CB1 receptor antagonist [{sup 3}H]SR141716A to quantify CB1R levels in different brain regions with in vitro receptor autoradiography. We found that the lack of DRD2 leads to a marked upregulation (approximately 2-fold increase) of CB1R in the cerebral cortex, the caudate-putamen, and the nucleus accumbens, which was reversed by chronic ethanol intake. The results suggest that DRD2-mediated dopaminergic neurotransmission and chronic ethanol intake exert an inhibitory effect on cannabinoid receptor expression in cortical and striatal regions implicated in the reinforcing and addictive properties of ethanol.

  16. Regression of Fibrosis after Chronic Stimulation of Cannabinoid CB2 Receptor in Cirrhotic Rats

    PubMed Central

    Muñoz-Luque, Javier; Ros, Josefa; Fernández-Varo, Guillermo; Tugues, Sònia; Morales-Ruiz, Manuel; Alvarez, Carlos E.; Friedman, Scott L.; Arroyo, Vicente; Jiménez, Wladimiro

    2010-01-01

    Two cannabinoid (CB) receptor subtypes, CB1 and CB2, have been cloned and characterized. Among other activities, receptor activation by cannabinoid ligands may result in pro- or antifibrogenic effects depending on their interaction with CB1 or CB2, respectively. In the current study, we investigated whether selective activation of hepatic CB2 modifies collagen abundance in cirrhotic rats with ascites. mRNA and protein expression of CB receptors in the liver of control and cirrhotic rats was assessed by reverse transcription-polymerase chain reaction, Western blot, and immunohistochemistry. The effect of chronically activating the CB2 receptor was investigated in cirrhotic rats with ascites treated daily (9 days) with the CB2 receptor-selective agonist 3-(1,1-dimethylbutyl)-1-deoxy-Δ8-tetrahydrocannabinol (JWH-133). At the end of treatment, mean arterial pressure and portal pressure were measured, and liver samples were obtained to evaluate infiltrate of mononuclear cells, hepatic apoptosis, α-smooth muscle actin (SMA) expression, collagen content, and matrix metalloproteinase (MMP)-2 abundance in all animals. JWH-133 improved arterial pressure, decreased the inflammatory infiltrate, reduced the number of activated stellate cells, increased apoptosis in nonparenchymal cells located in the margin of the septa, and decreased fibrosis compared with cirrhotic rats treated with vehicle. This was associated with decreased α-SMA and collagen I and increased MMP-2 in the hepatic tissue of cirrhotic rats treated with the CB2 agonist compared with untreated cirrhotic animals. Therefore, selective activation of hepatic CB2 receptors significantly reduces hepatic collagen content in rats with pre-existing cirrhosis, thus raising the possibility of using selective CB2 agonists for the treatment of hepatic fibrosis in human cirrhosis. PMID:18029545

  17. Control of Spasticity in a Multiple Sclerosis Model is mediated by CB1, not CB2, Cannabinoid Receptors

    PubMed Central

    Pryce, G; Baker, D

    2007-01-01

    Background and Purpose: There is increasing evidence to suggest that cannabis can ameliorate muscle-spasticity in multiple sclerosis, as was objectively shown in experimental autoimmune encephalomyelitis models. The purpose of this study was to investigate further the involvement of CB1 and CB2 cannabinoid receptors in the control of experimental spasticity. Experimental approach: Spasticity was induced in wildtype and CB1-deficient mice following the development of relapsing, experimental autoimmune encephalomyelitis. Spastic-hindlimb stiffness was measured by the resistance to flexion against a strain gauge following the administration of CB1 and CB2 agonists. Key Results: As previously suggested, some CB2-selective agonists (RWJ400065) could inhibit spasticity. Importantly, however, the anti-spastic activity of RWJ400065 and the therapeutic effect of non-selective CB1/CB2 agonists (R(+)WIN55,212–2 and CP55, 940) was lost in spastic, CB1-deficit mice. Conclusions and Implications: The CB1 receptor controls spasticity and cross-reactivity to this receptor appears to account for the therapeutic action of some CB2 agonists. As cannabinoid-induced psychoactivity is also mediated by the CB1 receptor, it will be difficult to truly dissociate the therapeutic effects from the well-known, adverse effects of cannabinoids when using cannabis as a medicine. The lack of knowledge on the true diversity of the cannabinoid system coupled with the lack of total specificity of current cannabinoid reagents makes interpretation of in vivo results difficult, if using a purely pharmacological approach. Gene knockout technology provides an important tool in target validation and indicates that the CB1 receptor is the main cannabinoid target for an anti-spastic effect. PMID:17220914

  18. Species differences in cannabinoid receptor 2 (CNR2 gene): identification of novel human and rodent CB2 isoforms, differential tissue expression, and regulation by cannabinoid receptor ligands

    PubMed Central

    Liu, Qing-Rong; Pan, Chun-Hung; Hishimoto, Akitoyo; Li, Chuan-Yun; Xi, Zheng-Xiong; Llorente-Berzal, Alvaro; Viveros, Maria-Paz; Ishiguro, Hiroki; Arinami, Tadao; Onaivi, Emmanuel Shan; Uhl, George R.

    2009-01-01

    Cannabinoids, endocannabinoids and marijuana activate two well-characterized cannabinoid receptors (CBRs), CB1-Rs and CB2-Rs. The expression of CB1-Rs in the brain and periphery has been well studied but neuronal CB2-Rs have received much less attention than CB1-Rs. Many studies have now identified and characterized functional glial and neuronal CB2-Rs in the central nervous system. However, many features of CB2-R gene structure, regulation and variation remain poorly characterized in comparison to the CB1-R. Here, we report on the discovery of a novel human CB2 gene promoter encoding testis (CB2A) isoform with starting exon located ca 45 kb upstream from the previously identified promoter encoding the spleen isoform (CB2B). The 5′ exons of both CB2 isoforms are untranslated 5′UTRs and alternatively spliced to the major protein coding exon of the CB2 gene. CB2A is expressed higher in testis and brain than CB2B that is expressed higher in other peripheral tissues than CB2A. Species comparison found that the CB2 gene of human, rat and mouse genomes deviated in their gene structures and isoform expression patterns. mCB2A expression was increased significantly in the cerebellum of mice treated with the CB-R mixed agonist, WIN55212-2. These results provide much improved information about CB2 gene structure and its human and rodent variants that should be considered in developing CB2-R-based therapeutic agents. PMID:19496827

  19. Clinical Significance of Cannabinoid Receptors CB1 and CB2 Expression in Human Malignant and Benign Thyroid Lesions

    PubMed Central

    Lakiotaki, Eleftheria; Giaginis, Constantinos; Tolia, Maria; Alexandrou, Paraskevi; Delladetsima, Ioanna; Giannopoulou, Ioanna; Kyrgias, George; Patsouris, Efstratios; Theocharis, Stamatios

    2015-01-01

    The endocannabinoid system is comprised of cannabinoid receptors (CB1 and CB2), their endogenous ligands (endocannabinoids), and proteins responsible for their metabolism participate in many different functions indispensable to homeostatic regulation in several tissues, exerting also antitumorigenic effects. The present study aimed to evaluate the clinical significance of CB1 and CB2 expression in human benign and malignant thyroid lesions. CB1 and CB2 proteins' expression was assessed immunohistochemically on paraffin-embedded thyroid tissues obtained from 87 patients with benign (n = 43) and malignant (n = 44) lesions and was statistically analyzed with clinicopathological parameters, follicular cells' proliferative capacity, and risk of recurrence rate estimated according to the American Thyroid Association (ATA) staging system. Enhanced CB1 and CB2 expression was significantly more frequently observed in malignant compared to benign thyroid lesions (p = 0.0010 and p = 0.0005, resp.). Enhanced CB1 and CB2 expression was also significantly more frequently observed in papillary carcinomas compared to hyperplastic nodules (p = 0.0097 and p = 0.0110, resp.). In malignant thyroid lesions, elevated CB2 expression was significantly associated with the presence of lymph node metastases (p = 0.0301). Enhanced CB2 expression was also more frequently observed in malignant thyroid cases with presence of capsular (p = 0.1165), lymphatic (p = 0.1989), and vascular invasion (p = 0.0555), as well as in those with increased risk of recurrence rate (p = 0.1165), at a nonsignificant level though, whereas CB1 expression was not associated with any of the clinicopathological parameters examined. Our data suggest that CB receptors may be involved in malignant thyroid transformation and especially CB2 receptor could serve as useful biomarker and potential therapeutic target in thyroid neoplasia. PMID:26539529

  20. Cannabinoid Receptor Activation Modifies NMDA Receptor Mediated Release of Intracellular Calcium: Implications for Endocannabinoid Control of Hippocampal Neural Plasticity

    PubMed Central

    Hampson, Robert E.; Miller, Frances; Palchik, Guillermo; Deadwyler, Sam A.

    2011-01-01

    Chronic activation or inhibition of cannabinoid receptors (CB1) leads to continuous suppression of neuronal plasticity in hippocampus and other brain regions, suggesting that endocannabinoids may have a functional role in synaptic processes that produce state-dependent transient modulation of hippocampal cell activity. In support of this, it has previously been shown in vitro that cannabinoid CB1 receptors modulate second messenger systems in hippocampal neurons that can modulate intracellular ion channels, including channels which release calcium from intracellular stores. Here we demonstrate in hippocampal slices a similar endocannabinoid action on excitatory glutamatergic synapses via modulation of NMDA-receptor mediated intracellular calcium levels in confocal imaged neurons. Calcium entry through glutamatergic NMDA-mediated ion channels increases intracellular calcium concentrations via modulation of release from ryanodine-sensitive channels in endoplasmic reticulum. The studies reported here show that NMDA-elicited increases in Calcium Green fluorescence are enhanced by CB1 receptor antagonists (i.e. rimonabant), and inhibited by CB1 agonists (i.e. WIN 55,212-2). Suppression of endocannabinoid breakdown by either reuptake inhibition (AM404) or fatty-acid amide hydrolase inhibition (URB597) produced suppression of NMDA elicited calcium increases comparable to WIN 55,212-2, while enhancement of calcium release provoked by endocannabinoid receptor antagonists (Rimonabant) was shown to depend on the blockade of CB1 receptor mediated de-phosphorylation of Ryanodine receptors. Such CB1 receptor modulation of NMDA elicited increases in intracellular calcium may account for the respective disruption and enhancement by CB1 agents of trial-specific hippocampal neuron ensemble firing patterns during performance of a short-term memory task, reported previously from this laboratory. PMID:21288475

  1. Neuronal Expression of CB2 Cannabinoid Receptor mRNAs in the Mouse Hippocampus

    PubMed Central

    Li, Yong; Kim, Jimok

    2015-01-01

    In the brain, CB1 cannabinoid receptors primarily mediate the effects of cannabinoids, but CB2 cannabinoid receptors (CB2Rs) have recently been discovered in the nervous system and also implicated in neuromodulatory roles. To understand the mechanisms of CB2R functions in the brain, it is essential to localize CB2Rs, but the types of cells expressing CB2Rs have been controversial. Unequivocal localization of CB2Rs in the brain has been impeded in part by the low expression levels of CB2Rs and poor specificity of detection methods. Here, we used an ultrasensitive and specific in situ hybridization method called the RNAscope to determine the spatial pattern of CB2R mRNA expression in the mouse hippocampus. CB2R mRNAs were mostly expressed in a subset of excitatory and inhibitory neurons in the CA1, CA3 and dentate gyrus areas, but rarely in microglia. CB2R knock-out mice were used as a negative control. Using the quantitative real-time polymerase chain reaction, we also found that the temporal pattern of CB2R mRNA expression was stable during postnatal development. Consistent with previous reports, the immunological detection of CB2Rs was not reliable, implying extremely low levels of the protein expression and/or insufficient specificity of the current anti-CB2R antibodies. Our findings of the expression patterns of CB2R mRNAs may help determine the cell types involved in, and hence the mechanisms of, the CB2R-mediated neuromodulation. PMID:26515747

  2. [Endomorphins--endogenous ligands of the mu-opioid receptor].

    PubMed

    Perlikowska, Renata; Fichna, Jakub; Janecka, Anna

    2009-01-01

    Two endogenous opioid peptides with extremely high mu-opioid receptor affinity and selectivity, endomorphin-1 and endomorphin-2, were: discovered and isolated from the mammalian brain in 1997. Endomorphins are amidated tetrapeptides, structurally different from so called typical opioids: enkephalins, dynorphins and endorphins. A protein precursor of endomorphins and a gene encoding their sequence remain unknown. Endomorphins are unable to cross the blood-brain barrier because of their low hydrophobicity. In animal models, these peptides turned out to be very potent in relieving neuropathic and inflammatory pain. In comparison with morphine, a prototype opioid receptor ligand, endomorphins produces less undesired side effects. In this article we describe the discovery of endomorphins, their cellular localization and functions in the organism, as well as their structure-activity relationships and biodegradation pathways.

  3. Distinct second extracellular loop structures of the brain cannabinoid CB(1) receptor: implication in ligand binding and receptor function.

    PubMed

    Shim, Joong-Youn; Rudd, James; Ding, Tomas T

    2011-02-01

    The G-protein-coupled receptor (GPCR) second extracellular loop (E2) is known to play an important role in receptor structure and function. The brain cannabinoid (CB(1)) receptor is unique in that it lacks the interloop E2 disulfide linkage to the transmembrane (TM) helical bundle, a characteristic of many GPCRs. Recent mutation studies of the CB(1) receptor, however, suggest the presence of an alternative intraloop disulfide bond between two E2 Cys residues. Considering the oxidation state of these Cys residues, we determine the molecular structures of the 17-residue E2 in the dithiol form (E2(dithiol)) and in the disulfide form (E2(disulfide)) of the CB(1) receptor in a fully hydrated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer, using a combination of simulated annealing and molecular dynamics simulation approaches. We characterize the CB(1) receptor models with these two E2 forms, CB(1)(E2(dithiol)) and CB(1)(E2(disulfide)), by analyzing interaction energy, contact number, core crevice, and cross correlation. The results show that the distinct E2 structures interact differently with the TM helical bundle and uniquely modify the TM helical topology, suggesting that E2 of the CB(1) receptor plays a critical role in stabilizing receptor structure, regulating ligand binding, and ultimately modulating receptor activation. Further studies on the role of E2 of the CB(1) receptor are warranted, particularly comparisons of the ligand-bound form with the present ligand-free form.

  4. Chronic cannabinoid receptor stimulation selectively prevents motor impairments in a mouse model of Huntington's disease.

    PubMed

    Pietropaolo, Susanna; Bellocchio, Luigi; Ruiz-Calvo, Andrea; Cabanas, Magali; Du, Zhuowei; Guzmán, Manuel; Garret, Maurice; Cho, Yoon H

    2015-02-01

    Huntington's disease (HD) is a devastating neurodegenerative disease characterized by a progressive decline in motor abilities, as well as in cognitive and social behaviors. Most of these behavioral deficits are recapitulated in the R6/1 transgenic mouse, which can therefore be used as an experimental model to identify the neurobiological substrates of HD pathology and to design novel therapeutic approaches. The endocannabinoid system (ECS) is a relevant candidate to participate in the etiopathology of HD as it is a key modulator of brain function, especially in areas primarily affected by HD dysfunction such as the striatum. Thus, some studies have demonstrated an association between HD progression and alterations in the expression of several ECS elements, thereby suggesting that improving ECS function may constitute a useful strategy to eliminate or at least delay the appearance of HD symptoms. Here this hypothesis was specifically tested by evaluating whether the administration of a well-characterized cannabinoid receptor agonist (WIN 55,212), either acutely or chronically, improves the HD-like symptoms in R6/1 mice. While acute treatment did not change the behavioral phenotype of transgenic animals, chronic administration was able to prevent the appearance of motor deficits, to increase the number of striatal huntingtin inclusions and to prevent the loss of striatal medium-sized spiny neurons, without affecting the social or cognitive alterations. These findings suggest that prolonged administration of cannabinoid receptor agonists could be an appropriate strategy for selectively improving motor symptoms and stimulating neuroprotective processes in HD patients.

  5. Stimulation of cannabinoid receptors by using Rubus coreanus extracts to control osteoporosis in aged male rats.

    PubMed

    Lim, Hae-Kyoung; Lee, Hye-Rim; Do, Sun Hee

    2015-06-01

    A substantial proportion of men with prostatic disease have an increased risk of bone loss. In the present study, we investigated the effects of Rubus coreanus Miquel (RCM) extracts on osteoporosis that occurs with N-methyl-N-nitrosourea (MNU)-induced prostatic hyperplasia. The rats used in this study were categorized into groups of healthy controls, rats treated with MNU, and rats treated with MNU and RCM. The rats were sacrificed after 10 weeks of RCM treatment, after which ultrasonography, serum biochemical tests, histopathological examinations, immunohistochemical analysis, and semi-quantitative reverse-transcription polymerase chain reaction analysis were performed. There were no marked differences in body weight gain and the size and weight of the prostate gland between the MNU group and the MNU and RCM group. However, treatment with RCM inhibited osteoclastic osteolysis and reduced dysplastic progress in the prostate gland, as observed by histopathological evaluation and by analyzing changes in the levels of bone regulatory factors. In addition, the group treated with MNU and RCM had higher expression levels of cannabinoid receptors-1, -2, and osteoprotegerin. These results indicate that the anti-osteoporotic effect of RCM in prostatic hyperplasia is attributable to the cannabinoid receptor-related upregulation of osteoblastogenesis and inhibition of prostatic hyperplasia. The results of the present study suggest that treatment with RCM may benefit osteoporotic patients with prostatic disease by simultaneously altering the activation of osteoblasts and osteoclasts.

  6. Cannabinoid receptor interacting protein suppresses agonist-driven CB1 receptor internalization and regulates receptor replenishment in an agonist-biased manner.

    PubMed

    Blume, Lawrence C; Leone-Kabler, Sandra; Luessen, Deborah J; Marrs, Glen S; Lyons, Erica; Bass, Caroline E; Chen, Rong; Selley, Dana E; Howlett, Allyn C

    2016-11-01

    Cannabinoid receptor interacting protein 1a (CRIP1a) is a CB1 receptor (CB1 R) distal C-terminus-associated protein that modulates CB1 R signaling via G proteins, and CB1 R down-regulation but not desensitization (Blume et al. [2015] Cell Signal., 27, 716-726; Smith et al. [2015] Mol. Pharmacol., 87, 747-765). In this study, we determined the involvement of CRIP1a in CB1 R plasma membrane trafficking. To follow the effects of agonists and antagonists on cell surface CB1 Rs, we utilized the genetically homogeneous cloned neuronal cell line N18TG2, which endogenously expresses both CB1 R and CRIP1a, and exhibits a well-characterized endocannabinoid signaling system. We developed stable CRIP1a-over-expressing and CRIP1a-siRNA-silenced knockdown clones to investigate gene dose effects of CRIP1a on CB1 R plasma membrane expression. Results indicate that CP55940 or WIN55212-2 (10 nM, 5 min) reduced cell surface CB1 R by a dynamin- and clathrin-dependent process, and this was attenuated by CRIP1a over-expression. CP55940-mediated cell surface CB1 R loss was followed by a cycloheximide-sensitive recovery of surface receptors (30-120 min), suggesting the requirement for new protein synthesis. In contrast, WIN55212-2-mediated cell surface CB1 Rs recovered only in CRIP1a knockdown cells. Changes in CRIP1a expression levels did not affect a transient rimonabant (10 nM)-mediated increase in cell surface CB1 Rs, which is postulated to be as a result of rimonabant effects on 'non-agonist-driven' internalization. These studies demonstrate a novel role for CRIP1a in agonist-driven CB1 R cell surface regulation postulated to occur by two mechanisms: 1) attenuating internalization that is agonist-mediated, but not that in the absence of exogenous agonists, and 2) biased agonist-dependent trafficking of de novo synthesized receptor to the cell surface.

  7. Peripheral and central CB1 cannabinoid receptors control stress-induced impairment of memory consolidation

    PubMed Central

    Busquets-Garcia, Arnau; Gomis-González, Maria; Srivastava, Raj Kamal; Cutando, Laura; Ortega-Alvaro, Antonio; Ruehle, Sabine; Remmers, Floortje; Bindila, Laura; Bellocchio, Luigi; Marsicano, Giovanni; Lutz, Beat; Maldonado, Rafael

    2016-01-01

    Stressful events can generate emotional memories linked to the traumatic incident, but they also can impair the formation of nonemotional memories. Although the impact of stress on emotional memories is well studied, much less is known about the influence of the emotional state on the formation of nonemotional memories. We used the novel object-recognition task as a model of nonemotional memory in mice to investigate the underlying mechanism of the deleterious effect of stress on memory consolidation. Systemic, hippocampal, and peripheral blockade of cannabinoid type-1 (CB1) receptors abolished the stress-induced memory impairment. Genetic deletion and rescue of CB1 receptors in specific cell types revealed that the CB1 receptor population specifically in dopamine β-hydroxylase (DBH)-expressing cells is both necessary and sufficient for stress-induced impairment of memory consolidation, but CB1 receptors present in other neuronal populations are not involved. Strikingly, pharmacological manipulations in mice expressing CB1 receptors exclusively in DBH+ cells revealed that both hippocampal and peripheral receptors mediate the impact of stress on memory consolidation. Thus, CB1 receptors on adrenergic and noradrenergic cells provide previously unrecognized cross-talk between central and peripheral mechanisms in the stress-dependent regulation of nonemotional memory consolidation, suggesting new potential avenues for the treatment of cognitive aspects on stress-related disorders. PMID:27528659

  8. Tumor-promoting effects of cannabinoid receptor type 1 in human melanoma cells.

    PubMed

    Carpi, Sara; Fogli, Stefano; Polini, Beatrice; Montagnani, Valentina; Podestà, Adriano; Breschi, Maria Cristina; Romanini, Antonella; Stecca, Barbara; Nieri, Paola

    2017-04-01

    The role of endocannabinoid system in melanoma development and progression is actually not fully understood. This study was aimed at clarifying whether cannabinoid-type 1 (CB1) receptor may function as tumor-promoting or -suppressing signal in human cutaneous melanoma. CB1 receptor expression was measured in human melanoma cell lines by real-time PCR. A genetic deletion of CB1 receptors in selected melanoma cells was carried out by using three different short hairpin RNAs (shRNAs). Performance of target gene silencing was verified by real-time PCR and Western blot. The effects of CB1 receptor silencing on cell growth, clonogenicity, migration capability, cell cycle progression, and activation of mitogenic signals was tested. Lentiviral shRNAs vectors targeting different regions of the human CB1 gene led to a significant reduction in CB1 receptor mRNA and a near complete loss of CB1 receptor protein, compared to control vector (LV-c). The number of viable cells, the colony-forming ability and cell migration were significantly reduced in cells transduced with CB1 lentiviral shRNAs compared to LV-c. Cell cycle analyses showed arrest at G1/S phase. p-Akt and p-ERK expression were decreased in transduced versus control cells. Findings of this study suggest that CB1 receptor might function as tumor-promoting signal in human cutaneous melanoma.

  9. Bimodal control of fear-coping strategies by CB₁ cannabinoid receptors.

    PubMed

    Metna-Laurent, Mathilde; Soria-Gómez, Edgar; Verrier, Danièle; Conforzi, Martina; Jégo, Pierrick; Lafenêtre, Pauline; Marsicano, Giovanni

    2012-05-23

    To maximize their chances of survival, animals need to rapidly and efficiently respond to aversive situations. These responses can be classified as active or passive and depend on the specific nature of threats, but also on individual fear coping styles. In this study, we show that the control of excitatory and inhibitory brain neurons by type-1 cannabinoid (CB₁) receptors is a key determinant of fear coping strategies in mice. In classical fear conditioning, a switch between initially predominant passive fear responses (freezing) and active behaviors (escape attempts and risk assessment) develops over time. Constitutive genetic deletion of CB₁ receptors in CB₁⁻/⁻ mice disrupted this pattern by favoring passive responses. This phenotype can be ascribed to endocannabinoid control of excitatory neurons, because it was reproduced in conditional mutant mice lacking CB₁ receptors from cortical glutamatergic neurons. CB₁ receptor deletion from GABAergic brain neurons led to the opposite phenotype, characterized by the predominance of active coping. The CB₁ receptor agonist Δ⁹-tetrahydrocannabinol exerted a biphasic control of fear coping strategies, with lower and higher doses favoring active and passive responses, respectively. Finally, viral re-expression of CB₁ receptors in the amygdala of CB₁⁻/⁻ mice restored the normal switch between the two coping strategies. These data strongly suggest that CB₁ receptor signaling bimodally controls the spontaneous adoption of active or passive coping strategies in individuals. This primary function of the endocannabinoid system in shaping individual behavioral traits should be considered when studying the mechanisms of physiological and pathological fear.

  10. Pharmacological blockade of either cannabinoid CB1 or CB2 receptors prevents both cocaine-induced conditioned locomotion and cocaine-induced reduction of cell proliferation in the hippocampus of adult male rat.

    PubMed

    Blanco-Calvo, Eduardo; Rivera, Patricia; Arrabal, Sergio; Vargas, Antonio; Pavón, Francisco Javier; Serrano, Antonia; Castilla-Ortega, Estela; Galeano, Pablo; Rubio, Leticia; Suárez, Juan; Rodriguez de Fonseca, Fernando

    2014-01-01

    Addiction to major drugs of abuse, such as cocaine, has recently been linked to alterations in adult neurogenesis in the hippocampus. The endogenous cannabinoid system modulates this proliferative response as demonstrated by the finding that pharmacological activation/blockade of cannabinoid CB1 and CB2 receptors not only modulates neurogenesis but also modulates cell death in the brain. In the present study, we evaluated whether the endogenous cannabinoid system affects cocaine-induced alterations in cell proliferation. To this end, we examined whether pharmacological blockade of either CB1 (Rimonabant, 3 mg/kg) or CB2 receptors (AM630, 3 mg/kg) would affect cell proliferation [the cells were labeled with 5-bromo-2'-deoxyuridine (BrdU)] in the subventricular zone (SVZ) of the lateral ventricle and the dentate subgranular zone (SGZ). Additionally, we measured cell apoptosis (as monitored by the expression of cleaved caspase-3) and glial activation [by analyzing the expression of glial fibrillary acidic protein (GFAP) and Iba-1] in the striatum and hippocampus during acute and repeated (4 days) cocaine administration (20 mg/kg). The results showed that acute cocaine exposure decreased the number of BrdU-immunoreactive (ir) cells in the SVZ and SGZ. In contrast, repeated cocaine exposure reduced the number of BrdU-ir cells only in the SVZ. Both acute and repeated cocaine exposure increased the number of cleaved caspase-3-, GFAP- and Iba1-ir cells in the hippocampus, and this effect was counteracted by AM630 or Rimonabant, which increased the number of BrdU-, GFAP-, and Iba1-ir cells in the hippocampus. These results indicate that the changes in neurogenic, apoptotic and gliotic processes that were produced by repeated cocaine administration were normalized by pharmacological blockade of CB1 and CB2. The restorative effects of cannabinoid receptor blockade on hippocampal cell proliferation were associated with the prevention of the induction of conditioned locomotion

  11. The effects of cannabinoids on the brain.

    PubMed

    Ameri, A

    1999-07-01

    Cannabinoids have a long history of consumption for recreational and medical reasons. The primary active constituent of the hemp plant Cannabis sativa is delta9-tetrahydrocannabinol (delta9-THC). In humans, psychoactive cannabinoids produce euphoria, enhancement of sensory perception, tachycardia, antinociception, difficulties in concentration and impairment of memory. The cognitive deficiencies seem to persist after withdrawal. The toxicity of marijuana has been underestimated for a long time, since recent findings revealed delta9-THC-induced cell death with shrinkage of neurons and DNA fragmentation in the hippocampus. The acute effects of cannabinoids as well as the development of tolerance are mediated by G protein-coupled cannabinoid receptors. The CB1 receptor and its splice variant CB1A, are found predominantly in the brain with highest densities in the hippocampus, cerebellum and striatum. The CB2 receptor is found predominantly in the spleen and in haemopoietic cells and has only 44% overall nucleotide sequence identity with the CB1 receptor. The existence of this receptor provided the molecular basis for the immunosuppressive actions of marijuana. The CB1 receptor mediates inhibition of adenylate cyclase, inhibition of N- and P/Q-type calcium channels, stimulation of potassium channels, and activation of mitogen-activated protein kinase. The CB2 receptor mediates inhibition of adenylate cyclase and activation of mitogen-activated protein kinase. The discovery of endogenous cannabinoid receptor ligands, anandamide (N-arachidonylethanolamine) and 2-arachidonylglycerol made the notion of a central cannabinoid neuromodulatory system plausible. Anandamide is released from neurons upon depolarization through a mechanism that requires calcium-dependent cleavage from a phospholipid precursor in neuronal membranes. The release of anandamide is followed by rapid uptake into the plasma and hydrolysis by fatty-acid amidohydrolase. The psychoactive cannabinoids

  12. Cannabinoid CB2 receptor agonists protect the striatum against malonate toxicity: relevance for Huntington's disease.

    PubMed

    Sagredo, Onintza; González, Sara; Aroyo, Ilia; Pazos, María Ruth; Benito, Cristina; Lastres-Becker, Isabel; Romero, Juan P; Tolón, Rosa M; Mechoulam, Raphael; Brouillet, Emmanuel; Romero, Julián; Fernández-Ruiz, Javier

    2009-08-15

    Cannabinoid agonists might serve as neuroprotective agents in neurodegenerative disorders. Here, we examined this hypothesis in a rat model of Huntington's disease (HD) generated by intrastriatal injection of the mitochondrial complex II inhibitor malonate. Our results showed that only compounds able to activate CB2 receptors were capable of protecting striatal projection neurons from malonate-induced death. That CB2 receptor agonists are neuroprotective was confirmed by using the selective CB2 receptor antagonist, SR144528, and by the observation that mice deficient in CB2 receptor were more sensitive to malonate than wild-type animals. CB2 receptors are scarce in the striatum in healthy conditions, but they are markedly upregulated after the lesion with malonate. Studies of double immunostaining revealed a significant presence of CB2 receptors in cells labeled with the marker of reactive microglia OX-42, and also in cells labeled with GFAP (a marker of astrocytes). We further showed that the activation of CB2 receptors significantly reduced the levels of tumor necrosis factor-alpha (TNF-alpha) that had been increased by the lesion with malonate. In summary, our results demonstrate that stimulation of CB2 receptors protect the striatum against malonate toxicity, likely through a mechanism involving glial cells, in particular reactive microglial cells in which CB2 receptors would be upregulated in response to the lesion. Activation of these receptors would reduce the generation of proinflammatory molecules like TNF-alpha. Altogether, our results support the hypothesis that CB2 receptors could constitute a therapeutic target to slowdown neurodegeneration in HD.

  13. Brain-derived neurotrophic factor controls cannabinoid CB1 receptor function in the striatum.

    PubMed

    De Chiara, Valentina; Angelucci, Francesco; Rossi, Silvia; Musella, Alessandra; Cavasinni, Francesca; Cantarella, Cristina; Mataluni, Giorgia; Sacchetti, Lucia; Napolitano, Francesco; Castelli, Maura; Caltagirone, Carlo; Bernardi, Giorgio; Maccarrone, Mauro; Usiello, Alessandro; Centonze, Diego

    2010-06-16

    The role of brain-derived neurotrophic factor (BDNF) in emotional processes suggests an interaction with the endocannabinoid system. Here, we addressed the functional interplay between BDNF and cannabinoid CB(1) receptors (CB(1)Rs) in the striatum, a brain area in which both BDNF and CB(1)s play a role in the emotional consequences of stress and of rewarding experiences. BDNF potently inhibited CB(1)R function in the striatum, through a mechanism mediated by altered cholesterol metabolism and membrane lipid raft function. The effect of BDNF was restricted to CB(1)Rs controlling GABA-mediated IPSCs (CB(1)R(GABA)), whereas CB(1)Rs modulating glutamate transmission and GABA(B) receptors were not affected. The action of BDNF on CB(1)R(GABA) function was tyrosine kinase dependent and was complete even after receptor sensitization with cocaine or environmental manipulations activating the dopamine (DA)-dependent reward system. In mice lacking one copy of the BDNF gene (BDNF(+/-)), CB(1)R(GABA) responses were potentiated and were preserved from the action of haloperidol, a DA D(2) receptor (D(2)R) antagonist able to fully abolish CB(1)R(GABA) function in rewarded animals. Haloperidol also enhanced BDNF levels in the striatum, suggesting that this neurotrophin may act as a downstream effector of D(2)Rs in the modulation of cannabinoid signaling. Accordingly, 5 d cocaine exposure both reduced striatal BDNF levels and increased CB(1)R(GABA) activity, through a mechanism dependent on D(2)Rs. The present study identifies a novel mechanism of CB(1)R regulation mediated by BDNF and cholesterol metabolism and provides some evidence that DA D(2)R-dependent modulation of striatal CB(1)R activity is mediated by this neurotrophin.

  14. Effect of the cannabinoid receptor-1 antagonist rimonabant on inflammation in mice with diet-induced obesity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We studied whether cannabinoid receptor (CB1) blockade with rimonabant has an anti-inflammatory effect in obese mice, and whether this effect depends on weight loss and/or diet consumption. High-fat diet (HFD)-induced obese mice were treated orally with rimonabant (HFD-R) or vehicle (HFD-V) for 4 we...

  15. Is lipid signaling through cannabinoid 2 receptors part of a protective system?

    PubMed Central

    Pacher, P.; Mechoulam, R.

    2011-01-01

    The mammalian body has a highly developed immune system which guards against continuous invading protein attacks and aims at preventing, attenuating or repairing the inflicted damage. It is conceivable that through evolution analogous biological protective systems have been evolved against non-protein attacks. There is emerging evidence that lipid endocannabinoid signaling through cannabinoid 2 (CB2) receptors may represent an example/part of such a protective system/armamentarium. Inflammation/tissue injury triggers rapid elevations in local endocannabinoid levels, which in turn regulate signaling responses in immune and other cells modulating their critical functions. Changes in endocannabinoid levels and/or CB2 receptor expressions have been reported in almost all diseases affecting humans, ranging from cardiovascular, gastrointestinal, liver, kidney, neurodegenerative, psychiatric, bone, skin, auto-immune, lung disorders to pain and cancer, and modulating CB2 receptor activity holds tremendous therapeutic potential in these pathologies. While CB2 receptor activation in general mediates immunosuppressive effects, which limit inflammation and associated tissue injury in large number of pathological conditions, in some disease states activation of the CB2 receptor may enhance or even trigger tissue damage, which will also be discussed alongside the protective actions of the CB2 receptor stimulation with endocannabinoids or synthetic agonists, and the possible biological mechanisms involved in these effects. PMID:21295074

  16. Cannabinoid receptor antagonists AM251 and AM630 activate TRPA1 in sensory neurons.

    PubMed

    Patil, Mayur; Patwardhan, Amol; Salas, Margaux M; Hargreaves, Kenneth M; Akopian, Armen N

    2011-09-01

    Cannabinoid receptor antagonists have been utilized extensively in vivo as well as in vitro, but their selectivity has not been fully examined. We investigated activation of sensory neurons by two cannabinoid antagonists - AM251 and AM630. AM251 and AM630 activated trigeminal (TG) sensory neurons in a concentration-dependent fashion (threshold 1 μM). AM251 and AM630 responses are mediated by the TRPA1 channel in a majority (90-95%) of small-to-medium TG sensory neurons. AM630 (1-100 μM), but not AM251, was a significantly more potent agonist in cells co-expressing both TRPA1 and TRPV1 channels. We next evaluated AM630 and AM251 effects on TRPV1- and TRPA1-mediated responses in TG neurons. Capsaicin (CAP) effects were inhibited by pre-treatment with AM630, but not AM251. Mustard oil (MO) and WIN55,212-2 (WIN) TRPA1 mediated responses were also inhibited by pre-treatment with AM630, but not AM251 (25 uM each). Co-treatment of neurons with WIN and either AM630 or AM251 had opposite effects: AM630 sensitized WIN responses, whereas AM251 inhibited WIN responses. WIN-induced inhibition of CAP responses in sensory neurons was reversed by AM630 pre-treatment and AM251 co-treatment (25 μM each), as these conditions inhibit WIN responses. Hindpaw injections of AM630 and AM251 did not produce nocifensive behaviors. However, both compounds modulated CAP-induced thermal hyperalgesia in wild-type mice and rats, but not TRPA1 null-mutant mice. AMs also partially regulate WIN inhibition of CAP-induced thermal hyperalgesia in a TRPA1-dependent fashion. In summary, these findings demonstrate alternative targets for the cannabinoid antagonists, AM251 and AM630, in peripheral antihyperalgesia which involve certain TRP channels.

  17. Chronic nicotine alters cannabinoid-mediated locomotor activity and receptor density in periadolescent but not adult male rats

    PubMed Central

    Werling, Linda L.; Reed, Stephanie Collins; Wade, Dean; Izenwasser, Sari

    2009-01-01

    A significant number of youths use cigarettes, and more than half of the youths who smoke daily also use illicit drugs. The focus of these studies is on how exposure to nicotine affects subsequent responses to both nicotine and cannabinoids in adolescents compared with adults. We have shown previously that chronic treatment with nicotine produces sensitization to its locomotor-activating effects in female and adult rats but not male adolescent rats. To better understand the effects of nicotine on adolescent and adult rats, rats were injected with nicotine or saline for 7 days and, on day 8, either challenged with delta-9-tetrahydrocannabinol (Δ9-THC) or the cannabinoid agonist CP 55,940 and tested for locomotor activity, or the brains were removed for quantitative autoradiography studies of the cannabinoid1 receptor. A separate group of rats was treated with nicotine plus the cannabinoid antagonist AM 251 and then challenged with CP 55,940. In adolescent male rats, nicotine administration led to sensitization to the locomotor-decreasing effects of both Δ9-THC and CP 55,940, but in adult male rats, the response to either drug was unchanged compared to controls. The effect of nicotine on CP 55,940-mediated locomotor activity was blocked by co-administration of AM 251 with the nicotine. Further, cannabinoid receptor density was increased in the prelimbic prefrontal cortex, ventral tegmental area, and select regions of the hippocampus in adolescent male rats pretreated with nicotine compared to vehicle-treated controls. There were no significant changes in cannabinoid receptor binding, however, in any of the brain regions examined in adult males pretreated with nicotine. The prelimbic prefrontal cortex and the hippocampus have been shown previously to be involved in stimulant reinforcement; thus it is possible that these changes contribute to the unique behavioral effects of chronic nicotine and subsequent drug administration in adolescents compared with adults. PMID

  18. Synthesis and Biological Evaluation of Thiophene-Based Cannabinoid Receptor Type 2 Radiotracers for PET Imaging.

    PubMed

    Haider, Ahmed; Müller Herde, Adrienne; Slavik, Roger; Weber, Markus; Mugnaini, Claudia; Ligresti, Alessia; Schibli, Roger; Mu, Linjing; Mensah Ametamey, Simon

    2016-01-01

    Over the past two decades, our understanding of the endocannabinoid system has greatly improved due to the wealth of results obtained from exploratory studies. Currently, two cannabinoid receptor subtypes have been well-characterized. The cannabinoid receptor type 1 (CB1) is widely expressed in the central nervous system, while the levels of the cannabinoid receptor type 2 (CB2) in the brain and spinal cord of healthy individuals are relatively low. However, recent studies demonstrated a CB2 upregulation on activated microglia upon neuroinflammation, an indicator of neurodegeneration. Our research group aims to develop a suitable positron emission tomography (PET) tracer to visualize the CB2 receptor in patients suffering from neurodegenerative diseases. Herein we report two novel thiophene-based (11)C-labeled PET ligands designated [(11)C]AAT-015 and [(11)C]AAT-778. The reference compounds were synthesized using Gewald reaction conditions to obtain the aminothiophene intermediates, followed by amide formation. Saponification of the esters provided their corresponding precursors. Binding affinity studies revealed Ki-values of 3.3 ± 0.5 nM (CB2) and 1.0 ± 0.2 μM (CB1) for AAT-015. AAT-778 showed similar Ki-values of 4.3 ± 0.7 nM (CB2) and 1.1 ± 0.1 μM (CB1). Radiosynthesis was carried out under basic conditions using [(11)C]iodomethane as methylating agent. After semi-preparative HPLC purification both radiolabeled compounds were obtained in 99% radiochemical purity and the radiochemical yields ranged from 12 to 37%. Specific activity was between 96 and 449 GBq/μmol for both tracers. In order to demonstrate CB2 specificity of [(11)C]AAT-015 and [(11)C]AAT-778, we carried out autoradiography studies using CB2-positive mouse/rat spleen tissues. The obtained results revealed unspecific binding in spleen tissue that was not blocked by an excess of CB2-specific ligand GW402833. For in vivo analysis, [(11)C]AAT-015 was administered to healthy rats via tail

  19. Synthesis and Biological Evaluation of Thiophene-Based Cannabinoid Receptor Type 2 Radiotracers for PET Imaging

    PubMed Central

    Haider, Ahmed; Müller Herde, Adrienne; Slavik, Roger; Weber, Markus; Mugnaini, Claudia; Ligresti, Alessia; Schibli, Roger; Mu, Linjing; Mensah Ametamey, Simon

    2016-01-01

    Over the past two decades, our understanding of the endocannabinoid system has greatly improved due to the wealth of results obtained from exploratory studies. Currently, two cannabinoid receptor subtypes have been well-characterized. The cannabinoid receptor type 1 (CB1) is widely expressed in the central nervous system, while the levels of the cannabinoid receptor type 2 (CB2) in the brain and spinal cord of healthy individuals are relatively low. However, recent studies demonstrated a CB2 upregulation on activated microglia upon neuroinflammation, an indicator of neurodegeneration. Our research group aims to develop a suitable positron emission tomography (PET) tracer to visualize the CB2 receptor in patients suffering from neurodegenerative diseases. Herein we report two novel thiophene-based 11C-labeled PET ligands designated [11C]AAT-015 and [11C]AAT-778. The reference compounds were synthesized using Gewald reaction conditions to obtain the aminothiophene intermediates, followed by amide formation. Saponification of the esters provided their corresponding precursors. Binding affinity studies revealed Ki-values of 3.3 ± 0.5 nM (CB2) and 1.0 ± 0.2 μM (CB1) for AAT-015. AAT-778 showed similar Ki-values of 4.3 ± 0.7 nM (CB2) and 1.1 ± 0.1 μM (CB1). Radiosynthesis was carried out under basic conditions using [11C]iodomethane as methylating agent. After semi-preparative HPLC purification both radiolabeled compounds were obtained in 99% radiochemical purity and the radiochemical yields ranged from 12 to 37%. Specific activity was between 96 and 449 GBq/μmol for both tracers. In order to demonstrate CB2 specificity of [11C]AAT-015 and [11C]AAT-778, we carried out autoradiography studies using CB2-positive mouse/rat spleen tissues. The obtained results revealed unspecific binding in spleen tissue that was not blocked by an excess of CB2-specific ligand GW402833. For in vivo analysis, [11C]AAT-015 was administered to healthy rats via tail-vein injection

  20. Cytochrome P450-mediated oxidative metabolism of abused synthetic cannabinoids found in K2/Spice: identification of novel cannabinoid receptor ligands.

    PubMed

    Chimalakonda, Krishna C; Seely, Kathryn A; Bratton, Stacie M; Brents, Lisa K; Moran, Cindy L; Endres, Gregory W; James, Laura P; Hollenberg, Paul F; Prather, Paul L; Radominska-Pandya, Anna; Moran, Jeffery H

    2012-11-01

    Abuse of synthetic cannabinoids (SCs), such as [1-naphthalenyl-(1-pentyl-1H-indol-3-yl]-methanone (JWH-018) and [1-(5-fluoropentyl)-1H-indol-3-yl]-1-naphthalenyl-methanone (AM2201), is increasing at an alarming rate. Although very little is known about the metabolism and toxicology of these popular designer drugs, mass spectrometric analysis of human urine specimens after JWH-018 and AM2201 exposure identified monohydroxylated and carboxylated derivatives as major metabolites. The present study extends these initial findings by testing the hypothesis that JWH-018 and its fluorinated counterpart AM2201 are subject to cytochrome P450 (P450)-mediated oxidation, forming potent hydroxylated metabolites that retain significant affinity and activity at the cannabinoid 1 (CB(1)) receptor. Kinetic analysis using human liver microsomes and recombinant human protein identified CYP2C9 and CYP1A2 as major P450s involved in the oxidation of the JWH-018 and AM2201. In vitro metabolite formation mirrored human urinary metabolic profiles, and each of the primary enzymes exhibited high affinity (K(m) = 0.81-7.3 μM) and low to high reaction velocities (V(max) = 0.0053-2.7 nmol of product · min(-1) · nmol protein(-1)). The contribution of CYP2C19, 2D6, 2E1, and 3A4 in the hepatic metabolic clearance of these synthetic cannabinoids was minimal (f(m) = <0.2). In vitro studies demonstrated that the primary metabolites produced in humans display high affinity and intrinsic activity at the CB(1) receptor, which was attenuated by the CB(1) receptor antagonist (6aR,10aR)-3-(1-methanesulfonylamino-4-hexyn-6-yl)-6a,7,10,10a-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran (O-2050). Results from the present study provide critical, missing data related to potential toxicological properties of "K2" parent compounds and their human metabolites, including mechanism(s) of action at cannabinoid receptors.

  1. Functional selectivity in CB(2) cannabinoid receptor signaling and regulation: implications for the therapeutic potential of CB(2) ligands.

    PubMed

    Atwood, Brady K; Wager-Miller, James; Haskins, Christopher; Straiker, Alex; Mackie, Ken

    2012-02-01

    Receptor internalization increases the flexibility and scope of G protein-coupled receptor (GPCR) signaling. CB(1) and CB(2) cannabinoid receptors undergo internalization after sustained exposure to agonists. However, it is not known whether different agonists internalize CB(2) to different extents. Because CB(2) is a promising therapeutic target, understanding its trafficking in response to different agonists is necessary for a complete understanding of its biology. Here we profile a number of cannabinoid receptor ligands and provide evidence for marked functional selectivity of cannabinoid receptor internalization. Classic, aminoalkylindole, bicyclic, cannabilactone, iminothiazole cannabinoid, and endocannabinoid ligands varied greatly in their effects on CB(1) and CB(2) trafficking. Our most striking finding was that (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo-[1,2,3-d,e]-1,4-benzoxazin-6-yl]-1-naphthalenyl-methanone (WIN55,212-2) (and other aminoalkylindoles) failed to promote CB(2) receptor internalization, whereas 5-(1,1-dimethylheptyl)-2-(5-hydroxy-2-(3-hydroxypropyl)cyclohexyl)phenol (CP55,940) robustly internalized CB(2) receptors. Furthermore, WIN55,212-2 competitively antagonized CP55,940-induced CB(2) internalization. Despite these differences in internalization, both compounds activated CB(2) receptors as measured by extracellular signal-regulated kinase 1/2 phosphorylation and recruitment of β-arrestin(2) to the membrane. In contrast, whereas CP55,940 inhibited voltage-gated calcium channels via CB(2) receptor activation, WIN55,212-2 was ineffective on its own and antagonized the effects of CP55,940. On the basis of the differences we found between these two ligands, we also tested the effects of other cannabinoids on these signaling pathways and found additional evidence for functional selectivity of CB(2) ligands. These novel data highlight that WIN55,212-2 and other cannabinoids show strong functional selectivity at CB(2

  2. Benzyl-1,2,4-triazoles as CB1 Cannabinoid Receptor Ligands: Preparation and In Vitro Pharmacological Evaluation

    PubMed Central

    Hernandez-Folgado, Laura; Decara, Juan; Rodríguez de Fonseca, Fernando; Goya, Pilar; Jagerovic, Nadine

    2016-01-01

    In a previous study, we have identified 3-alkyl-1,5-diaryl-1H-1,2,4-triazoles to be a novel class of cannabinoid type 1 receptor (CB1R) antagonists. In order to expand the number of cannabinoid ligands with a central 1,2,4-triazole scaffold, we have synthesized a novel series of 1-benzyl-1H-1,2,4-triazoles, and some of them were evaluated by CB1R radioligand binding assays. Compound 12a showed the most interesting pharmacological properties, possessing a CB1R affinity in the nanomolar range. PMID:27127651

  3. Benzyl-1,2,4-triazoles as CB 1 Cannabinoid Receptor Ligands: Preparation and In Vitro Pharmacological Evaluation.

    PubMed

    Hernandez-Folgado, Laura; Decara, Juan; Rodríguez de Fonseca, Fernando; Goya, Pilar; Jagerovic, Nadine

    2016-01-01

    In a previous study, we have identified 3-alkyl-1,5-diaryl-1H-1,2,4-triazoles to be a novel class of cannabinoid type 1 receptor (CB1R) antagonists. In order to expand the number of cannabinoid ligands with a central 1,2,4-triazole scaffold, we have synthesized a novel series of 1-benzyl-1H-1,2,4-triazoles, and some of them were evaluated by CB1R radioligand binding assays. Compound 12a showed the most interesting pharmacological properties, possessing a CB1R affinity in the nanomolar range.

  4. Targeting the cannabinoid system for pain relief?

    PubMed

    Chiou, Lih-Chu; Hu, Sherry Shu-Jung; Ho, Yu-Cheng

    2013-12-01

    Marijuana has been used to relieve pain for centuries, but its analgesic mechanism has only been understood during the past two decades. It is mainly mediated by its constituents, cannabinoids, through activating central cannabinoid 1 (CB1) receptors, as well as peripheral CB1 and CB2 receptors. CB2-selective agonists have the benefit of lacking CB1 receptor-mediated CNS side effects. Anandamide and 2-arachidonoylglycerol (2-AG) are two intensively studied endogenous lipid ligands of cannabinoid receptors, termed endocannabinoids, which are synthesized on demand and rapidly degraded. Thus, inhibitors of their degradation enzymes, fatty acid amide hydrolase and monoacylglycerol lipase (MAGL), respectively, may be superior to direct cannabinoid receptor ligands as a promising strategy for pain relief. In addition to the antinociceptive properties of exogenous cannabinoids and endocannabinoids, involving their biosynthesis and degradation processes, we also review recent studies that revealed a novel analgesic mechanism, involving 2-AG in the periaqueductal gray (PAG), a midbrain region for initiating descending pain inhibition. It is initiated by Gq-protein-coupled receptor (GqPCR) activation of the phospholipase C (PLC)-diacylglycerol lipase (DAGL) enzymatic cascade, generating 2-AG that produces inhibition of GABAergic transmission (disinhibition) in the PAG, thereby leading to analgesia. This GqPCR-PLC-DAGL-2-AG retrograde disinhibition mechanism in the PAG can be initiated by activating type 5 metabotropic glutamate receptor (mGluR5), muscarinic acetylcholine (M1/M3), and orexin (OX1) receptors. mGluR5-mediated disinhibition can be initiated by glutamate transporter inhibitors, or indirectly by substance P, neurotensin, cholecystokinin, capsaicin, and AM404, the bioactive metabolite of acetaminophen in the brain. The putative role of 2-AG generated after activating the above neurotransmitter receptors in stress-induced analgesia is also discussed.

  5. Architecture of cannabinoid signaling in mouse retina

    PubMed Central

    Hu, Sherry Shu-Jung; Arnold, Andy; Hutchens, Jacqueline M.; Radicke, Josh; Cravatt, Benjamin F.; Wager-Miller, Jim; Mackie, Ken; Straiker, Alex

    2010-01-01

    Cannabinoid receptors and their ligands constitute an endogenous signaling system that is found throughout the body, including the eye. This system can be activated by Δ9-tetrahydrocannabinol, a major drug of abuse. Cannabinoids offer considerable therapeutic potential in modulating ocular immune and inflammatory responses and in regulating intraocular pressure. The location of cannabinoid receptors 1 (CB1) in the retina is known, but recently a constellation of proteins has been identified that produce and break down endocannabinoids (eCBs) and modulate CB1 function. Localization of these proteins is critical to defining specific cannabinoid signaling circuitry in the retina. Here we show the localization of diacylglycerol lipase α and β (DGLα/β), implicated in the production of the eCB 2-arachidonoyl glycerol (2-AG); monoacylglycerol lipase (MGL) and α/β-hydrolase domain 6 (ABHD6), both implicated in the breakdown of 2-AG; cannabinoid receptor interacting protein 1a (CRIP1a), a protein that may modulate CB1 function; Fatty acid amide hydrolase (FAAH) and N-acylethanolamine-hydrolyzing acid amidase (NAAA) which have been shown to break down the eCB anandamide and related acyl amides. In our most prominent finding, DGLα is present in post-synaptic Type 1 OFF cone bipolar cells juxtaposed to CB1-containing cone photoreceptor terminals. Interestingly, CRIP1a is reliably presynaptic to DGLα, consistent with a possible role in cannabinoid signaling, NAAA is restricted to retinal pigment epithelium (RPE), while DGLβ is limited to retinal blood vessels. These results taken together with previous anatomic and functional studies define specific cannabinoid circuitry likely to modulate eCB signaling at the first synapse of the retina as well as in the inner plexiform layer (IPL). PMID:20653038

  6. Brain structural and clinical changes after first episode psychosis: Focus on cannabinoid receptor 1 polymorphisms.

    PubMed

    Suárez-Pinilla, Paula; Roiz-Santiañez, Roberto; Ortiz-García de la Foz, Víctor; Guest, Paul C; Ayesa-Arriola, Rosa; Córdova-Palomera, Aldo; Tordesillas-Gutierrez, Diana; Crespo-Facorro, Benedicto

    2015-08-30

    Cannabinoid receptor 1 (CNR1) gene polymorphisms have been associated with central and peripheral effects of cannabis and schizophrenia pathophysiology. Here, we have tested whether three CNR1 variants (rs1049353, rs1535255 and rs2023239) are associated with changes in brain volumes, body mass index (BMI) or psychopathological scores in a 3-year longitudinal study of 65 first-episode psychosis patients. The rs1049353 at-risk allele was significantly associated with a greater reduction of caudate volume, and the rs2023239 T/C polymorphism showed a significant decrease in thalamic volume after the 3-year period. For those who were not cannabis users, the rs1535255 and rs2023239 polymorphisms had effects in lateral ventricle (LV), and LV and white matter, respectively. The rs2023239 variant also was associated with significant improvements in positive and negative symptoms of schizophrenia. There was no significant effect of any of the variants on changes in BMI over the 3-year study. Finally, an interaction between all three polymorphisms was found involving evolution of positive symptoms. These findings suggest that the cannabinoid pathway is associated with schizophrenia evolution over time. However, further studies using larger cohorts are needed to confirm these results. If confirmed, the present findings could lead in subsequent investigations for identification of novel drug targets for improved treatment of patients suffering from schizophrenia.

  7. Astrocytic expression of cannabinoid type 1 receptor in rat and human sclerotic hippocampi

    PubMed Central

    Meng, Xian-Dong; Wei, Dong; Li, Juan; Kang, Jun-Jun; Wu, Chen; Ma, Lei; Yang, Feng; Zhu, Ge-Min; Ou-Yang, Tang-Peng; Liu, Ying-Ying; Jiang, Wen

    2014-01-01

    Cannabinoid type 1 receptor (CB1R), which is traditionally located on axon terminals, plays an important role in the pathology of epilepsy and neurodegenerative diseases by modulating synaptic transmission. Using the pilocarpine model of chronic spontaneous recurrent seizures, which mimics the main features of mesial temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS) in humans, we examined the expression of CB1R in hippocampal astrocytes of epileptic rats. Furthermore, we also examined the expression of astrocytic CB1R in the resected hippocampi from patients with medically refractory mesial TLE. Using immunofluorescent double labeling, we found increased expression of astrocytic CB1R in hippocampi of epileptic rats, whereas expression of astrocytic CB1R was not detectable in hippocampi of saline treated animals. Furthermore, CB1R was also found in some astrocytes in sclerotic hippocampi in a subset of patients with intractable mesial TLE. Detection with immune electron microscopy showed that the expression of CB1R was increased in astrocytes of epileptic rats and modest levels of CB1R were also found on the astrocytic membrane of sclerotic hippocampi. These results suggest that increased expression of astrocytic CB1R in sclerotic hippocampi might be involved in the cellular basis of the effects of cannabinoids on epilepsy. PMID:25031702

  8. On the effects of CP 55-940 and other cannabinoid receptor agonists in C6 and U373 cell lines.

    PubMed

    Ortega, A; Rangel-López, E; Hidalgo-Miranda, A; Morales, A; Ruiz-García, E; Meneses-García, A; Herrera-Gómez, A; Aguilar-Ponce, J L; González-Herrera, I G; Guevara-Salazar, P; Prospero-García, O; Del Angel, S A

    2015-10-01

    Cannabinoid receptor (CBs) agonists affect the growth of tumor cells via activation of deadly cascades. The spectrum of action of these agents and the precise role of the endocannabinoid system (ECS) on oncogenic processes remain elusive. Herein we compared the effects of synthetic (CP 55-940 and WIN 55,212-2) and endogenous (anandamide or AEA) CBs agonists (10-20 μM) on morphological changes, cell viability, and induction of apoptosis in primary astrocytes and in two glioblastoma cell lines (C6 and U373 cells) in order to characterize their possible differential actions on brain tumor cells. None of the CBs agonist tested induced changes in cell viability or morphology in primary astrocytes. In contrast, CP 55-940 significantly decreased cell viability in C6 and U373 cells at 5 days of treatment, whereas AEA and WIN 55,212-2 moderately decreased cell viability in both cell lines. Treatment of U373 and C6 for 3 and 5 days with AEA or WIN 55,212-2 produced discrete morphological changes in cell bodies, whereas the exposure to CP 55-940 induced soma degradation. CP 55-940 also induced apoptosis in both C6 and U373 cell lines. Our results support a more effective action of CP 55-940 to produce cell death of both cell lines through apoptotic mechanisms. Comparative aspects between cannabinoids with different profiles are necessary for the design of potential treatments against glial tumors.

  9. Regulatory role of the cannabinoid CB2 receptor in stress-induced neuroinflammation in mice

    PubMed Central

    Zoppi, S; Madrigal, J L; Caso, J R; García-Gutiérrez, M S; Manzanares, J; Leza, J C; García-Bueno, B

    2014-01-01

    Background and Purpose Stress exposure produces excitotoxicity and neuroinflammation, contributing to the cellular damage observed in stress-related neuropathologies. The endocannabinoids provide a homeostatic system, present in stress-responsive neural circuits. Here, we have assessed the possible regulatory role of cannabinoid CB2 receptors in stress-induced excitotoxicity and neuroinflammation. Experimental Approach We used wild type (WT), transgenic overexpressing CB2 receptors (CB2xP) and CB2 receptor knockout (CB2-KO) mice exposed to immobilization and acoustic stress (2 h·day−1 for 4 days). The CB2 receptor agonist JWH-133 was administered daily (2 mg·kg−1, i.p.) to WT and CB2-KO animals. Glutamate uptake was measured in synaptosomes from frontal cortex; Western blots and RT-PCR were used to measure proinflammatory cytokines, enzymes and mediators in homogenates of frontal cortex. Key Results Increased plasma corticosterone induced by stress was not modified by manipulating CB2 receptors. JWH-133 treatment or overexpression of CB2 receptors increased control levels of glutamate uptake, which were reduced by stress back to control levels. JWH-133 prevented the stress-induced increase in proinflammatory cytokines (TNF-α and CCL2), in NF-κB, and in NOS-2 and COX-2 and in the consequent cellular oxidative and nitrosative damage (lipid peroxidation). CB2xP mice exhibited anti-inflammatory or neuroprotective actions similar to those in JWH-133 pretreated animals. Conversely, lack of CB2 receptors (CB2-KO mice) exacerbated stress-induced neuroinflammatory responses and confirmed that effects of JWH-133 were mediated through CB2 receptors. Conclusions and Implications Pharmacological manipulation of CB2 receptors is a potential therapeutic strategy for the treatment of stress-related pathologies with a neuroinflammatory component, such as depression. PMID:24467609

  10. Cannabinoid modulation of alpha2 adrenergic receptor function in rodent medial prefrontal cortex

    PubMed Central

    Cathel, Alessandra M.; Reyes, Beverly A. S.; Wang, Qin; Palma, Jonathan; Mackie, Kenneth; Bockstaele, Elisabeth J. Van; Kirby, Lynn G.

    2014-01-01

    Endocannabinoids acting at the cannabinoid type 1 receptor (CB1R) are known to regulate attention, cognition and mood. Previous studies have shown that, in the rat medial prefrontal cortex (mPFC), CB1R agonists increase norepinephrine release, an effect that may be attributed, in part, to CB1Rs localized to noradrenergic axon terminals. The present study was aimed at further characterizing functional interactions between CB1R and adrenergic receptor (AR) systems in the mPFC using in-vitro intracellular electrophysiology and high-resolution neuroanatomical techniques. Whole-cell patch-clamp recordings of layer V/VI cortical pyramidal neurons in rats revealed that both acute and chronic treatment with the synthetic CB1R agonist WIN 55,212-2 blocked elevations in cortical pyramidal cell excitability and increases in input resistance evoked by the α2-adrenergic receptor (α2-AR) agonist clonidine, suggesting a desensitization of α2-ARs. These CB1R–α2-AR interactions were further shown to be both action potential- and gamma-aminobutyric acid-independent. To better define sites of cannabinoid–AR interactions, we localized α2A-ARs in a genetically modified mouse that expressed a hemoagglutinin (HA) tag downstream of the α2A-AR promoter. Light and electron microscopy indicated that HA-α2A-AR was distributed in axon terminals and somatodendritic processes especially in layer V of the mPFC. Triple-labeling immunocytochemistry revealed that α2A-AR and CB1R were localized to processes that contained dopamine-β-hydroxylase, a marker of norepinephrine. Furthermore, HA-α2A-AR was localized to processes that were directly apposed to CB1R. These findings suggest multiple sites of interaction between cortical cannabinoid–adrenergic systems that may contribute to understanding the effect of cannabinoids on executive functions and mood. PMID:25131562

  11. Mechanisms of Biased β-Arrestin-Mediated Signaling Downstream from the Cannabinoid 1 Receptor

    PubMed Central

    Delgado-Peraza, Francheska; Ahn, Kwang H.; Nogueras-Ortiz, Carlos; Mungrue, Imran N.; Mackie, Ken; Kendall, Debra A.

    2016-01-01

    Activation of G protein-coupled receptors results in multiple waves of signaling that are mediated by heterotrimeric G proteins and the scaffolding proteins β-arrestin 1/2. Ligands can elicit full or subsets of cellular responses, a concept defined as ligand bias or functional selectivity. However, our current understanding of β-arrestin-mediated signaling is still very limited. Here we provide a comprehensive view of β-arrestin-mediated signaling from the cannabinoid 1 receptor (CB1R). By using a signaling biased receptor, we define the cascades, specific receptor kinases, and molecular mechanism underlying β-arrestin-mediated signaling: We identify the interaction kinetics of CB1R and β-arrestin 1 during their endocytic trafficking as directly proportional to its efficacy. Finally, we demonstrate that signaling results in the control of genes clustered around prosurvival and proapoptotic functions among others. Together, these studies constitute a comprehensive description of β-arrestin-mediated signaling from CB1Rs and suggest modulation of receptor endocytic trafficking as a therapeutic approach to control β-arrestin-mediated signaling. PMID:27009233

  12. Cannabinoid type-1 receptor signaling in central serotonergic neurons regulates anxiety-like behavior and sociability

    PubMed Central

    Häring, Martin; Enk, Vanessa; Aparisi Rey, Alejandro; Loch, Sebastian; Ruiz de Azua, Inigo; Weber, Tillmann; Bartsch, Dusan; Monory, Krisztina; Lutz, Beat

    2015-01-01

    The endocannabinoid (eCB) system possesses neuromodulatory functions by influencing the release of various neurotransmitters, including γ-aminobutyric acid (GABA) and glutamate. A functional interaction between eCBs and the serotonergic system has already been suggested. Previously, we showed that cannabinoid type-1 (CB1) receptor mRNA and protein are localized in serotonergic neurons of the raphe nuclei, implying that the eCB system can modulate serotonergic functions. In order to substantiate the physiological role of the CB1 receptor in serotonergic neurons of the raphe nuclei, we generated serotonergic 5-hydroxytryptamine (5-HT) neuron-specific CB1 receptor-deficient mice, using the Cre/loxP system with a tamoxifen-inducible Cre recombinase under the control of the regulatory sequences of the tryptophan hydroxylase 2 gene (TPH2-CreERT2), thus, restricting the recombination to 5-HT neurons of the central nervous system (CNS). Applying several different behavioral paradigms, we revealed that mice lacking the CB1 receptor in serotonergic neurons are more anxious and less sociable than control littermates. Thus, we were able to show that functional CB1 receptor signaling in central serotonergic neurons modulates distinct behaviors in mice. PMID:26388750

  13. Potential role of the cannabinoid receptor CB1 in rapid eye movement sleep rebound.

    PubMed

    Navarro, L; Martínez-vargas, M; Murillo-rodríguez, E; Landa, A; Méndez-díaz, M; Prospéro-garcía, O

    2003-01-01

    Sleep is an unavoidable activity of the brain. The delay of the time to sleep (sleep deprivation), induces an increase of slow-wave sleep and rapid-eye-movement (REM) sleep (rebound) once the subject is allowed to sleep. This drive to sleep has been hypothesized to be dependent on the accumulation of sleep-inducing molecules and on the high expression of these molecule receptors. In this study we selectively deprived rats of REM sleep for 24 h by using the flowerpot technique. One group deprived of REM sleep was treated with SR141716A, a cannabinoid receptor 1 (CB1) receptor antagonist and then allowed to sleep for the next 4 h. Two other groups were killed, one immediately after the REM sleep deprivation period and the other after 2 h of REM sleep rebound (REM sleep deprivation plus 2 h of rebound). In both groups we determined the expression of the CB1 receptor and its mRNA. Results indicated that SR141716A prevents REM sleep rebound and REM sleep deprivation does not modify the expression of the CB1 protein or mRNA. However, REM sleep deprivation plus 2 h of sleep rebound increased the CB1 receptor protein and, slightly but significantly, decreased mRNA expression. These results suggest that endocannabinoids may be participating in the expression of REM sleep rebound.

  14. Comparative effects of chlorpyrifos in wild type and cannabinoid Cb1 receptor knockout mice

    SciTech Connect

    Baireddy, Praveena; Liu, Jing; Hinsdale, Myron; Pope, Carey

    2011-11-15

    Endocannabinoids (eCBs) modulate neurotransmission by inhibiting the release of a variety of neurotransmitters. The cannabinoid receptor agonist WIN 55.212-2 (WIN) can modulate organophosphorus (OP) anticholinesterase toxicity in rats, presumably by inhibiting acetylcholine (ACh) release. Some OP anticholinesterases also inhibit eCB-degrading enzymes. We studied the effects of the OP insecticide chlorpyrifos (CPF) on cholinergic signs of toxicity, cholinesterase activity and ACh release in tissues from wild type (+/+) and cannabinoid CB1 receptor knockout (-/-) mice. Mice of both genotypes (n = 5-6/treatment group) were challenged with CPF (300 mg/kg, 2 ml/kg in peanut oil, sc) and evaluated for functional and neurochemical changes. Both genotypes exhibited similar cholinergic signs and cholinesterase inhibition (82-95% at 48 h after dosing) in cortex, cerebellum and heart. WIN reduced depolarization-induced ACh release in vitro in hippocampal slices from wild type mice, but had no effect in hippocampal slices from knockouts or in striatal slices from either genotype. Chlorpyrifos oxon (CPO, 100 {mu}M) reduced release in hippocampal slices from both genotypes in vitro, but with a greater reduction in tissues from wild types (21% vs 12%). CPO had no significant in vitro effect on ACh release in striatum. CPF reduced ACh release in hippocampus from both genotypes ex vivo, but reduction was again significantly greater in tissues from wild types (52% vs 36%). In striatum, CPF led to a similar reduction (20-23%) in tissues from both genotypes. Thus, while CB1 deletion in mice had little influence on the expression of acute toxicity following CPF, CPF- or CPO-induced changes in ACh release appeared sensitive to modulation by CB1-mediated eCB signaling in a brain-regional manner. -- Highlights: Black-Right-Pointing-Pointer C57Bl/6 mice showed dose-related cholinergic toxicity following subcutaneous chlorpyrifos exposure. Black-Right-Pointing-Pointer Wild type and

  15. Activation of spinal and supraspinal cannabinoid-1 receptors lead to antinociception in a rat model of neuropathic spinal cord injury pain

    PubMed Central

    Hama, Aldric; Sagen, Jacqueline

    2011-01-01

    Activation of CNS cannabinoid subtype-1 (CB1) receptors has been shown to mediate the antinociceptive and other effects of systemically administered CB receptor agonists. The endogenous peptide CB receptor ligand hemopressin (HE) has previously demonstrated an antinociceptive effect in rats with a hind paw inflammation, without exhibiting characteristic CB1 receptor-mediated side-effects. The current study evaluated the effect of intrathecal (i.t.) and intracerebroventricular (i.c.v.) injection of HE in a rat model of neuropathic spinal cord injury (SCI) pain. The non-subtype selective CB receptor agonist WIN 55,212-2 was also centrally administered in SCI rats as a comparator. Four weeks following an acute compression of the mid-thoracic spinal cord, rats displayed markedly decreased hind paw withdrawal thresholds, indicative of below-level neuropathic pain. Central administration of WIN 55,212-2 significantly increased withdrawal thresholds, whereas HE did not. Hemopressin has been reported to block CB1 receptors in vitro, similar to the CB1 receptor antagonist rimonabant. Pretreatment with rimonabant completely blocked the antinociceptive effect of centrally administered WIN 55,212-2, but pretreatment with HE did not. While the data confirm that activation of either supraspinal or spinal CB1 receptors leads to significant antinociception in SCI rats, the current data do not support an antinociceptive effect from an acute blockade of central CB1 receptors, HE’s putative antinociceptive mechanism, in neuropathic SCI rats. Although such a mechanism could be useful in other models of pain with a significant inflammatory component, the current data indicate that activation of CB1 receptors is needed to ameliorate neuropathic SCI pain. PMID:21813113

  16. Synthetic Ligands of Cannabinoid Receptors Affect Dauer Formation in the Nematode Caenorhabditis elegans

    PubMed Central

    Reis Rodrigues, Pedro; Kaul, Tiffany K.; Ho, Jo-Hao; Lucanic, Mark; Burkewitz, Kristopher; Mair, William B.; Held, Jason M.; Bohn, Laura M.; Gill, Matthew S.

    2016-01-01

    Under adverse environmental conditions the nematode Caenorhabditis elegans can enter an alternate developmental stage called the dauer larva. To identify lipophilic signaling molecules that influence this process, we screened a library of bioactive lipids and found that AM251, an antagonist of the human cannabinoid (CB) receptor, suppresses dauer entry in daf-2 insulin receptor mutants. AM251 acted synergistically with glucose supplementation indicating that the metabolic status of the animal influenced the activity of this compound. Similarly, loss of function mutations in the energy-sensing AMP-activated kinase subunit, aak-2, enhanced the dauer-suppressing effects of AM251, while constitutive activation of aak-2 in neurons was sufficient to inhibit AM251 activity. Chemical epistasis experiments indicated that AM251 acts via G-protein signaling and requires the TGF-β ligand DAF-7, the insulin peptides DAF-28 and INS-6, and a functional ASI neuron to promote reproductive growth. AM251 also required the presence of the SER-5 serotonin receptor, but in vitro experiments suggest that this may not be via a direct interaction. Interestingly, we found that other antagonists of mammalian CB receptors also suppress dauer entry, while the nonselective CB receptor agonist, O-2545, not only inhibited the activity of AM251, but also was able to promote dauer entry when administered alone. Since worms do not have obvious orthologs of CB receptors, the effects of synthetic CBs on neuroendocrine signaling in C. elegans are likely to be mediated via another, as yet unknown, receptor mechanism. However, we cannot exclude the existence of a noncanonical CB receptor in C. elegans. PMID:27172180

  17. Cannabinoid 1 receptor promotes cardiac dysfunction, oxidative stress, inflammation, and fibrosis in diabetic cardiomyopathy.

    PubMed

    Rajesh, Mohanraj; Bátkai, Sándor; Kechrid, Malek; Mukhopadhyay, Partha; Lee, Wen-Shin; Horváth, Béla; Holovac, Eileen; Cinar, Resat; Liaudet, Lucas; Mackie, Ken; Haskó, György; Pacher, Pál

    2012-03-01

    Endocannabinoids and cannabinoid 1 (CB(1)) receptors have been implicated in cardiac dysfunction, inflammation, and cell death associated with various forms of shock, heart failure, and atherosclerosis, in addition to their recognized role in the development of various cardiovascular risk factors in obesity/metabolic syndrome and diabetes. In this study, we explored the role of CB(1) receptors in myocardial dysfunction, inflammation, oxidative/nitrative stress, cell death, and interrelated signaling pathways, using a mouse model of type 1 diabetic cardiomyopathy. Diabetic cardiomyopathy was characterized by increased myocardial endocannabinoid anandamide levels, oxidative/nitrative stress, activation of p38/Jun NH(2)-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs), enhanced inflammation (tumor necrosis factor-α, interleukin-1β, cyclooxygenase 2, intracellular adhesion molecule 1, and vascular cell adhesion molecule 1), increased expression of CB(1), advanced glycation end product (AGE) and angiotensin II type 1 receptors (receptor for advanced glycation end product [RAGE], angiotensin II receptor type 1 [AT(1)R]), p47(phox) NADPH oxidase subunit, β-myosin heavy chain isozyme switch, accumulation of AGE, fibrosis, and decreased expression of sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase (SERCA2a). Pharmacological inhibition or genetic deletion of CB(1) receptors attenuated the diabetes-induced cardiac dysfunction and the above-mentioned pathological alterations. Activation of CB(1) receptors by endocannabinoids may play an important role in the pathogenesis of diabetic cardiomyopathy by facilitating MAPK activation, AT(1)R expression/signaling, AGE accumulation, oxidative/nitrative stress, inflammation, and fibrosis. Conversely, CB(1) receptor inhibition may be beneficial in the treatment of diabetic cardiovascular complications.

  18. Highly selective CB(1) cannabinoid receptor ligands and novel CB(1)/VR(1) vanilloid receptor "hybrid" ligands.

    PubMed

    Di Marzo, V; Bisogno, T; De Petrocellis, L; Brandi, I; Jefferson, R G; Winckler, R L; Davis, J B; Dasse, O; Mahadevan, A; Razdan, R K; Martin, B R

    2001-02-23

    Anandamide and the metabolically stabler analogs, (R)-1'-methyl-2'-hydroxy-ethyl-arachidonamide (Met-AEA) and N-(3-methoxy-4-hydroxy-benzyl)-arachidonamide (arvanil), are CB(1) cannabinoid and VR(1) vanilloid receptors agonists. We synthesized 1',1'-dimethylheptyl-arvanil (O-1839) and six other AEA analogs obtained by addition of either a hydroxy, cyano, or bromo group on the C-20 atom of 1,1'-dimethylpentyl-Met-AEA (O-1811, O-1812 and O-1860, respectively) or 1,1'-dimethylpentyl-arvanil (O-1856, O-1895 and O-1861, respectively). The compounds were tested for their (i) affinity for CB(1) and CB(2) receptors, (ii) capability to activate VR1 receptors, (iii) inhibitory effect on the anandamide hydrolysis and on the anandamide membrane transporter, and (iv) cannabimimetic activity in the mouse 'tetrad' of in vivo assays. O-1812 is the first ligand ever proven to be highly (500- to 1000-fold) selective for CB(1) vs both VR(1) and CB(2) receptors, while O-1861 is the first true "hybrid" agonist of CB(1)/VR(1) receptors and a compound with potential therapeutic importance. The activities of the seven compounds in vivo did not correlate with their activities at either CB(1) or VR(1) receptors, thus suggesting the existence of other brain sites of action mediating some of their neurobehavioral actions in mice.

  19. Human Cannabinoid Receptor 2 Ligand-Interaction Motif: Transmembrane Helix 2 Cysteine, C2.59(89), as Determinant of Classical Cannabinoid Agonist Activity and Binding Pose.

    PubMed

    Zhou, Han; Peng, Yan; Halikhedkar, Aneetha; Fan, Pusheng; Janero, David R; Thakur, Ganesh A; Mercier, Richard W; Sun, Xin; Ma, Xiaoyu; Makriyannis, Alexandros

    2017-03-01

    Cannabinoid receptor 2 (CB2R)-dependent signaling is implicated in neuronal physiology and immune surveillance by brain microglia. Selective CB2R agonists hold therapeutic promise for inflammatory and other neurological disorders. Information on human CB2R (hCB2R) ligand-binding and functional domains is needed to inform the rational design and optimization of candidate druglike hCB2R agonists. Prior demonstration that hCB2R transmembrane helix 2 (TMH2) cysteine C2.59(89) reacts with small-molecule methanethiosulfonates showed that this cysteine residue is accessible to sulfhydryl derivatization reagents. We now report the design and application of two novel, pharmacologically active, high-affinity molecular probes, AM4073 and AM4099, as chemical reporters to interrogate directly the interaction of classical cannabinoid agonists with hCB2R cysteine residues. AM4073 has one electrophilic isothiocyanate (NCS) functionality at the C9 position of its cyclohexenyl C-ring, whereas AM4099 has NCS groups at that position and at the terminus of its aromatic A-ring C3 side chain. Pretreatment of wild-type hCB2R with either probe reduced subsequent [(3)H]CP55,940 specific binding by ∼60%. Conservative serine substitution of any hCB2R TMH cysteine residue except C2.59(89) did not affect the reduction of [(3)H]CP55,940 specific binding by either probe, suggesting that AM4073 and AM4099 interact irreversibly with this TMH2 cysteine. In contrast, AM841, an exceptionally potent hCB2R megagonist and direct AM4073/4099 congener bearing a single electrophilic NCS group at the terminus of its C3 side chain, had been demonstrated to bind covalently to TMH6 cysteine C6.47(257) and not C2.59(89). Molecular modeling indicates that the AM4073-hCB2R* interaction at C2.59(89) orients this classical cannabinoid away from TMH6 and toward the TMH2-TMH3 interface in the receptor's hydrophobic binding pocket, whereas the AM841-hCB2R* interaction at C6.47(257) favors agonist orientation toward

  20. Brain endogenous liver X receptor ligands selectively promote midbrain neurogenesis.

    PubMed

    Theofilopoulos, Spyridon; Wang, Yuqin; Kitambi, Satish Srinivas; Sacchetti, Paola; Sousa, Kyle M; Bodin, Karl; Kirk, Jayne; Saltó, Carmen; Gustafsson, Magnus; Toledo, Enrique M; Karu, Kersti; Gustafsson, Jan-Åke; Steffensen, Knut R; Ernfors, Patrik; Sjövall, Jan; Griffiths, William J; Arenas, Ernest

    2013-02-01

    Liver X receptors (Lxrα and Lxrβ) are ligand-dependent nuclear receptors critical for ventral midbrain neurogenesis in vivo. However, no endogenous midbrain Lxr ligand has so far been identified. Here we used LC/MS and functional assays to identify cholic acid as a new Lxr ligand. Moreover, 24(S),25-epoxycholesterol (24,25-EC) was found to be the most potent and abundant Lxr ligand in the developing mouse midbrain. Both Lxr ligands promoted neural development in an Lxr-dependent manner in zebrafish in vivo. Notably, each ligand selectively regulated the development of distinct midbrain neuronal populations. Whereas cholic acid increased survival and neurogenesis of Brn3a-positive red nucleus neurons, 24,25-EC promoted dopaminergic neurogenesis. These results identify an entirely new class of highly selective and cell type-specific regulators of neurogenesis and neuronal survival. Moreover, 24,25-EC promoted dopaminergic differentiation of embryonic stem cells, suggesting that Lxr ligands may thus contribute to the development of cell replacement and regenerative therapies for Parkinson's disease.

  1. Anti-inflammatory effects of cannabinoid CB2 receptor activation in endotoxin-induced uveitis

    PubMed Central

    Toguri, J T; Lehmann, C; Laprairie, R B; Szczesniak, A M; Zhou, J; Denovan-Wright, E M; Kelly, M E M

    2014-01-01

    Background and PurposeCannabinoid CB2 receptors mediate immunomodulation. Here, we investigated the effects of CB2 receptor ligands on leukocyte-endothelial adhesion and inflammatory mediator release in experimental endotoxin-induced uveitis (EIU). Experimental ApproachEIU was induced by intraocular injection of lipopolysaccharide (LPS, 20 ng·μL−1). Effects of the CB2 receptor agonist, HU308 (1.5% topical), the CB2 receptor antagonist, AM630 (2.5 mg·kg−1 i.v.), or a combination of both compounds on leukocyte-endothelial interactions were measured hourly for 6 h in rat iridial vasculature using intravital microscopy. Anti-inflammatory actions of HU308 were compared with those of clinical treatments for uveitis - dexamethasone, prednisolone and nepafenac. Transcription factors (NF-κB, AP-1) and inflammatory mediators (cytokines, chemokines and adhesion molecules) were measured in iris and ciliary body tissue. Key ResultsLeukocyte-endothelium adherence was increased in iridial microvasculature between 4–6 h after LPS. HU308 reduced this effect after LPS injection and decreased pro-inflammatory mediators: TNF-α, IL-1β, IL-6, CCL5 and CXCL2. AM630 blocked the actions of HU-308, and increased leukocyte-endothelium adhesion. HU-308 decreased levels of the transcription factors NF-κB and AP-1, while AM630 increased levels of NF-κB. Topical treatments with dexamethasone, prednisolone or nepafenac, failed to alter leukocyte adhesion or mitigate LPS-induced increases in inflammatory mediators during the 6 h of EIU. Conclusion and ImplicationsActivation of CB2 receptors was anti-inflammatory in a model of acute EIU and involved a reduction in NF-κB, AP-1 and inflammatory mediators. CB2 receptors may be promising drug targets for the development of novel ocular anti-inflammatory agents. Linked ArticlesThis article is part of a themed section on Cannabinoids 2013. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014

  2. Decreased Cocaine Motor Sensitization and Self-Administration in Mice Overexpressing Cannabinoid CB2 Receptors

    PubMed Central

    Aracil-Fernández, Auxiliadora; Trigo, José M; García-Gutiérrez, María S; Ortega-Álvaro, Antonio; Ternianov, Alexander; Navarro, Daniela; Robledo, Patricia; Berbel, Pere; Maldonado, Rafael; Manzanares, Jorge

    2012-01-01

    The potential involvement of the cannabinoid CB2 receptors (CB2r) in the adaptive responses induced by cocaine was studied in transgenic mice overexpressing the CB2r (CB2xP) and in wild-type (WT) littermates. For this purpose, the acute and sensitized locomotor responses to cocaine, conditioned place preference, and cocaine intravenous self-administration were evaluated. In addition, we assessed whether CB2r were localized in neurons and/or astrocytes, and whether they colocalized with dopamine D1 and D2 receptors (D1Dr and D2Dr). Dopamine (DA) extracellular levels in the nucleus accumbens (NAcc), and gene expression of tyrosine hydroxylase (TH) and DA transporter (DAT) in the ventral tegmental area (VTA), and μ-opioid and cannabinoid CB1 receptors in the NAcc were also studied in both genotypes. CB2xP mice showed decreased motor response to acute administration of cocaine (10–20 mg/kg) and cocaine-induced motor sensitization compared with WT mice. CB2xP mice presented cocaine-induced conditioned place aversion and self-administered less cocaine than WT mice. CB2r were found in neurons and astrocytes and colocalized with D2Dr in the VTA and NAcc. No significant differences in extracellular DA levels in the NAcc were observed between genotypes after cocaine administration. Under baseline conditions, TH and DAT gene expression was higher and μ-opioid receptor gene expression was lower in CB2xP than in WT mice. However, both genotypes showed similar changes in TH and μ-opioid receptor gene expression after cocaine challenge independently of the pretreatment received. Importantly, the cocaine challenge decreased DAT gene expression to a lesser extent in cocaine-pretreated CB2xP than in cocaine-pretreated WT mice. These results revealed that CB2r are involved in cocaine motor responses and cocaine self-administration, suggesting that this receptor could represent a promising target to develop novel treatments for cocaine addiction. PMID:22414816

  3. Bi-directional CB1 receptor-mediated cardiovascular effects of cannabinoids in anaesthetized rats: role of the paraventricular nucleus.

    PubMed

    Grzeda, E; Schlicker, E; Luczaj, W; Harasim, E; Baranowska-Kuczko, M; Malinowska, B

    2015-06-01

    The activation of cannabinoid CB1 receptors decreases and increases blood pressure (BP) in anaesthetized and conscious rats, respectively. The aim of our study was to check the possible involvement of CB1 receptors in the paraventricular nucleus of the hypothalamus (PVN) in the cardiovascular effects of cannabinoids in rats. Methanandamide (metabolically stable analogue of the endocannabinoid anandamide) and the synthetic cannabinoid receptor agonist CP55940 were microinjected into the PVN of urethane-anaesthetized rats twice (S1 and S2, 20 min apart). Receptor antagonists were administered intravenously (i.v.) 5 min before S1. Methanandamide and CP55940 decreased blood pressure by 15 - 20%. The CB1 receptor antagonist AM251 reversed the depressor effect into a pressor response of 20 - 30%. The pressor effect of CP55940 observed in the presence of AM251 i.v. was reduced by AM251 given additionally into the PVN but not by the i.v. injection of the CB2 antagonist SR144528 or the vanilloid TRPV1 antagonist ruthenium red. In the presence of the peripherally restricted CB1 receptor antagonist AM6545, CP55940 given into the PVN increased BP by 40%. AM6545 reversed the decrease in BP induced by CP55940 i.v. into a marked increase. Bilateral chemical lesion of the PVN by kainic acid abolished all cardiovascular effects of CP55940 i.v. In conclusion, the cannabinoid CP55940 administered to the PVN of urethane-anaesthetized rats can induce depressor and pressor effects. The direction of the response probably depends on the sympathetic tone. The centrally induced hypertensive response of CP55940 can, in addition, be masked by peripheral CB1 receptors.

  4. Cannabinoid CB2 receptor ligand profiling reveals biased signalling and off-target activity

    PubMed Central

    Soethoudt, Marjolein; Grether, Uwe; Fingerle, Jürgen; Grim, Travis W.; Fezza, Filomena; de Petrocellis, Luciano; Ullmer, Christoph; Rothenhäusler, Benno; Perret, Camille; van Gils, Noortje; Finlay, David; MacDonald, Christa; Chicca, Andrea; Gens, Marianela Dalghi; Stuart, Jordyn; de Vries, Henk; Mastrangelo, Nicolina; Xia, Lizi; Alachouzos, Georgios; Baggelaar, Marc P.; Martella, Andrea; Mock, Elliot D.; Deng, Hui; Heitman, Laura H.; Connor, Mark; Di Marzo, Vincenzo; Gertsch, Jürg; Lichtman, Aron H.; Maccarrone, Mauro; Pacher, Pal; Glass, Michelle; van der Stelt, Mario

    2017-01-01

    The cannabinoid CB2 receptor (CB2R) represents a promising therapeutic target for various forms of tissue injury and inflammatory diseases. Although numerous compounds have been developed and widely used to target CB2R, their selectivity, molecular mode of action and pharmacokinetic properties have been poorly characterized. Here we report the most extensive characterization of the molecular pharmacology of the most widely used CB2R ligands to date. In a collaborative effort between multiple academic and industry laboratories, we identify marked differences in the ability of certain agonists to activate distinct signalling pathways and to cause off-target effects. We reach a consensus that HU910, HU308 and JWH133 are the recommended selective CB2R agonists to study the role of CB2R in biological and disease processes. We believe that our unique approach would be highly suitable for the characterization of other therapeutic targets in drug discovery research. PMID:28045021

  5. Rimonabant: a cannabinoid receptor type 1 blocker for management of multiple cardiometabolic risk factors.

    PubMed

    Gelfand, Eli V; Cannon, Christopher P

    2006-05-16

    Rimonabant is a first selective blocker of the cannabinoid receptor type 1 (CB1) being developed for the treatment of multiple cardiometabolic risk factors, including abdominal obesity and smoking. In four large trials, after one year of treatment, rimonabant 20 mg led to greater weight loss and reduction in waist circumference compared with placebo. Therapy with rimonabant is also associated with favorable changes in serum lipid levels and an improvement in glycemic control in prediabetes patients and in type 2 diabetic patients. At the same dose, rimonabant significantly increased cigarette smoking quit rates as compared with placebo. Rimonabant seems to be well tolerated, with a primary side effect of mild nausea. As an agent with a novel mechanism of action, rimonabant has a potential to be a useful adjunct to lifestyle and behavior modification in treatment of multiple cardiometabolic risk factors, including abdominal obesity and smoking.

  6. Cannabinoid-2 receptor limits inflammation, oxidative/nitrosative stress and cell death in nephropathy

    PubMed Central

    Mukhopadhyay, Partha; Rajesh, Mohanraj; Pan, Hao; Patel, Vivek; Mukhopadhyay, Bani; Bátkai, Sándor; Gao, Bin; Haskó, György; Pacher, Pál

    2010-01-01

    Cisplatin is an important chemotherapeutic agent available; however the nephrotoxicity is limiting its clinical use. Enhanced inflammatory response and oxidative/nitrosative stress appear to play a key role in the development of cisplatin-induced nephropathy. Activation of cannabinoid-2 (CB2) receptors with selective agonists exerts anti-inflammatory and tissue protective effects in various disease models. We have investigated the role of CB2 receptors in cisplatin-induced nephrotoxicity using selective CB2 receptor agonist HU-308 and CB2 knockout mice. Cisplatin significantly increased inflammation (leukocyte infiltration, CXCL1/2, MCP-1, TNF-α and IL1β levels), expressions of adhesion molecule ICAM-1 and superoxide generating enzymes NOX2, NOX4 and NOX1, enhanced ROS generation, iNOS expression, nitrotyrosine formation, apoptotic and poly(ADP-ribose) polymerase-dependent cell death in the kidneys of mice, associated with marked histopathological damage and impaired renal function (elevated serum BUN and creatinine levels) 3 days following the administration of the drug. CB2 agonist attenuated the cisplatin-induced inflammatory response, oxidative/nitrosative stress and cell death in the kidney and improved renal function, while CB2 knockouts developed enhanced inflammation and tissue injury. Thus, the endocannabinoid system through CB2 receptors protects against cisplatin-induced kidney damage by attenuating inflammation and oxidative/nitrosative stress, and selective CB2 agonists may represent a promising novel approach to prevent this devastating complication of chemotherapy. PMID:19969072

  7. Type 2 cannabinoid receptor contributes to the physiological regulation of spermatogenesis.

    PubMed

    Di Giacomo, Daniele; De Domenico, Emanuela; Sette, Claudio; Geremia, Raffaele; Grimaldi, Paola

    2016-04-01

    Type 2 cannabinoid receptor (CB2) has been proposed to play a pivotal role in meiotic entry of male germ cells, similar to retinoic acid (RA). In this study, we showed that activation of CB2with the specific agonist JWH133 [3-(1',1'-dimethylbutyl)-1-deoxy-8-THC] (IC5010(-6)M) mimics epigenetic events induced by RA (IC5010(-7)M) in spermatogonia. Both JWH133 and RA treatments stimulate the expression of the meiotic genes c-KitandStra8, by up-regulating H3K4me3 and down-regulating H3K9me2 levels in genomic regions flanking the transcription start site. Moreover, both agents increase the expression ofPrdm9, the gene encoding a meiosis-specific histone, H3K4me3 methyltransferase, which marks hotspots of recombination in prophase I, thus resulting in a global increase in H3K4me3. Notably, prolonged administration of JWH133 to immature 7 dpp CD-1 mice induced an acceleration of the onset of spermatogenesis, whereas the specific CB2antagonist delayed germ cell differentiation. Thus, both hyper- and hypostimulation of CB2disrupted the temporal dynamics of the spermatogenic cycle. These findings highlight the importance of proper CB2signaling for the maintenance of a correct temporal progression of spermatogenesis and suggest a possible adverse effect of cannabis in deregulating this process.-Di Giacomo, D., De Domenico, E., Sette, C., Geremia, R., Grimaldi, P. Type 2 cannabinoid receptor contributes to the physiological regulation of spermatogenesis.

  8. Activation of cannabinoid CB2 receptor-mediated AMPK/CREB pathway reduces cerebral ischemic injury.

    PubMed

    Choi, In-Young; Ju, Chung; Anthony Jalin, Angela M A; Lee, Da In; Prather, Paul L; Kim, Won-Ki

    2013-03-01

    The type 2 cannabinoid receptor (CB2R) was recently shown to mediate neuroprotection in ischemic injury. However, the role of CB2Rs in the central nervous system, especially neuronal and glial CB2Rs in the cortex, remains unclear. We, therefore, investigated anti-ischemic mechanisms of cortical CB2R activation in various ischemic models. In rat cortical neurons/glia mixed cultures, a CB2R agonist, trans-caryophyllene (TC), decreased neuronal injury and mitochondrial depolarization caused by oxygen-glucose deprivation/re-oxygenation (OGD/R); these effects were reversed by the selective CB2R antagonist, AM630, but not by a type 1 cannabinoid receptor antagonist, AM251. Although it lacked free radical scavenging and antioxidant enzyme induction activities, TC reduced OGD/R-evoked mitochondrial dysfunction and intracellular oxidative stress. Western blot analysis demonstrated that TC enhanced phosphorylation of AMP-activated protein kinase (AMPK) and cAMP responsive element-binding protein (CREB), and increased expression of the CREB target gene product, brain-derived neurotrophic factor. However, TC failed to alter the activity of either Akt or extracellular signal-regulated kinase, two major CB2R signaling pathways. Selective AMPK and CREB inhibitors abolished the neuroprotective effects of TC. In rats, post-ischemic treatment with TC decreased cerebral infarct size and edema, and increased phosphorylated CREB and brain-derived neurotrophic factor expression in neurons. All protective effects of TC were reversed by co-administration with AM630. Collectively, these data demonstrate that cortical CB2R activation by TC ameliorates ischemic injury, potentially through modulation of AMPK/CREB signaling, and suggest that cortical CB2Rs might serve as a putative therapeutic target for cerebral ischemia.

  9. Altered pattern of cannabinoid type 1 receptor expression in adipose tissue of dysmetabolic and overweight patients.

    PubMed

    Sarzani, Riccardo; Bordicchia, Marica; Marcucci, Pierfrancesco; Bedetta, Samuele; Santini, Silvia; Giovagnoli, Andrea; Scappini, Lorena; Minardi, Daniele; Muzzonigro, Giovanni; Dessì-Fulgheri, Paolo; Rappelli, Alessandro

    2009-03-01

    In overweight patients (OW), the increased peripheral activity of the endocannabinoid system in visceral adipose tissue (VAT) may be mediated by cannabinoid type 1 (CB1) receptor expression. We determined whether CB1 receptor splice variants and messenger RNA (mRNA) levels in perirenal and subcutaneous adipose tissues are associated with obesity and metabolic syndrome (MetS). Gene expression with multiple-primers real-time polymerase chain reaction (TaqMan; Applied Biosystem, Weiterstadt, Germany) was performed to study VAT and paired subcutaneous adipose tissue (SAT) mRNA from 36 consecutive patients undergoing nephrectomy. Cannabinoid type 1A and CB1E mRNAs variants with the longer version of exon 4 were expressed. The CB1 expression in perirenal VAT significantly correlated with body mass index (BMI). Paired subcutaneous/perirenal samples from normal-weight patients (BMI < 25 kg/m(2)) showed higher CB1 expression in SAT (P = .002), whereas in OW (BMI > or = 25 kg/m(2)), the higher CB1 expression was in VAT (P = .038). In unpaired samples, SAT of normal-weight patients had significantly higher CB1 mRNA levels compared with SAT of OW, whereas higher CB1 expression (P = .009) was found in VAT of OW (n = 25). Overweight patients with increased visceral CB1 expression had higher waist circumference (P < .01), insulin (P < .01), and homeostasis model assessment index (P < .01). In addition, patients with the MetS (n = 22) showed higher CB1 expression in perirenal adipose tissues (P = .007). Visceral adipose CB1 expression correlated with BMI. Overweight patients and those with MetS showed a CB1 expression pattern supporting a CB1-mediated overactivity of the endocannabinoid system in human VAT.

  10. Modulation of breast cancer cell viability by a cannabinoid receptor 2 agonist, JWH-015, is calcium dependent

    PubMed Central

    Hanlon, Katherine E; Lozano-Ondoua, Alysia N; Umaretiya, Puja J; Symons-Liguori, Ashley M; Chandramouli, Anupama; Moy, Jamie K; Kwass, William K; Mantyh, Patrick W; Nelson, Mark A; Vanderah, Todd W

    2016-01-01

    Introduction Cannabinoid compounds, both nonspecific as well as agonists selective for either cannabinoid receptor 1 (CB1) or cannabinoid receptor 2 (CB2), have been shown to modulate the tumor microenvironment by inducing apoptosis in tumor cells in several model systems. The mechanism of this modulation remains only partially delineated, and activity induced via the CB1 and CB2 receptors may be distinct despite significant sequence homology and structural similarity of ligands. Methods The CB2-selective agonist JWH-015 was used to investigate mechanisms downstream of CB2 activation in mouse and human breast cancer cell lines in vitro and in a murine mammary tumor model. Results JWH-015 treatment significantly reduced primary tumor burden and metastasis of luciferase-tagged murine mammary carcinoma 4T1 cells in immunocompetent mice in vivo. Furthermore, JWH-015 reduced the viability of murine 4T1 and human MCF7 mammary carcinoma cells in vitro by inducing apoptosis. JWH-015-mediated reduction of breast cancer cell viability was not dependent on Gαi signaling in vitro or modified by classical pharmacological blockade of CB1, GPR55, TRPV1, or TRPA1 receptors. JWH-015 effects were calcium dependent and induced changes in MAPK/ERK signaling. Conclusion The results of this work characterize the actions of a CB2-selective agonist on breast cancer cells in a syngeneic murine model representing how a clinical presentation of cancer progression and metastasis may be significantly modulated by a G-protein-coupled receptor. PMID:27186076

  11. Distinct Second Extracellular Loop Structures of the Brain Cannabinoid CB1 Receptor: Implication in Ligand Binding and Receptor Function

    PubMed Central

    Shim, Joong-Youn; Rudd, James; Ding, Tomas T.

    2010-01-01

    The G-protein coupled receptor (GPCR) second extracellular loop (E2) is known to play an important role in receptor structure and function. The brain cannabinoid (CB1) receptor is unique in that it lacks the inter-loop E2 disulfide linkage to the transmembrane (TM) helical bundle, a characteristic of many GPCRs. Recent mutation studies of the CB1 receptor, however, suggest the presence of an alternative intra-loop disulfide bond between two E2 Cys residues. Considering the oxidation state of these Cys residues, we determine the molecular structures of the 17-residue E2 in the dithiol form (E2dithiol) and in the disulfide form (E2disulfide) of the CB1 receptor in a fully hydrated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer, employing a combination of simulated annealing (SA) and molecular dynamics (MD) simulation approaches. We characterize the CB1 receptor models with these two E2 forms, CB1(E2dithiol) and CB1(E2disulfide), by analyzing interaction energy, contact number, core crevice and cross-correlation. The results show that the distinct E2 structures interact differently with the TM helical bundle and uniquely modify the TM helical topology, suggesting that E2 plays a critical role in stabilizing receptor structure, regulating ligand binding, and ultimately modulating receptor activation. Further studies on the role of E2 of the CB1 receptor are warranted; particularly comparisons of the ligand-bound form with the present ligand-free form. PMID:21120862

  12. Adenosine A2A receptors enable the synaptic effects of cannabinoid CB1 receptors in the rodent striatum.

    PubMed

    Tebano, Maria Teresa; Martire, Alberto; Chiodi, Valentina; Pepponi, Rita; Ferrante, Antonella; Domenici, Maria Rosaria; Frank, Claudio; Chen, Jiang-Fan; Ledent, Catherine; Popoli, Patrizia

    2009-09-01

    Adenosine A(2A), cannabinoid CB(1) and metabotropic glutamate 5 (mGlu(5)) receptors are all highly expressed in the striatum. The aim of the present work was to investigate whether, and by which mechanisms, the above receptors interact in the regulation of striatal synaptic transmission. By extracellular field potentials (FPs) recordings in corticostriatal slices, we demonstrated that the ability of the selective type 1 cannabinoid receptor (CB(1)R) agonist WIN55,212-2 to depress synaptic transmission was prevented by the pharmacological blockade or the genetic inactivation of A(2A)Rs. Such a permissive effect of A(2A)Rs towards CB(1)Rs does not seem to occur pre-synaptically as the ability of WIN55,212-2 to increase the R2/R1 ratio under a protocol of paired-pulse stimulation was not modified by ZM241385. Furthermore, the effects of WIN55,212-2 were reduced in slices from mice lacking post-synaptic striatal A(2A)Rs. The selective mGlu(5)R agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG) potentiated the synaptic effects of WIN55,212-2, and such a potentiation was abolished by A(2A)R blockade. Unlike the synaptic effects, the ability of WIN55,212-2 to prevent NMDA-induced toxicity was not influenced by ZM241385. Altogether, these results show that the state of activation of A(2A)Rs regulates the synaptic effects of CB(1)Rs and that A(2A)Rs may control CB(1) effects also indirectly, namely through mGlu(5)Rs.

  13. CB1 cannabinoid receptor-mediated anandamide signaling mechanisms of the inferior colliculus modulate the haloperidol-induced catalepsy.

    PubMed

    Medeiros, P; de Freitas, R L; Silva, M O; Coimbra, N C; Melo-Thomas, L

    2016-11-19

    The inferior colliculus (IC), a midbrain structure that processes acoustic information of aversive nature, is distinguished from other auditory nuclei in the brainstem by its connections with structures of the motor system. Previous evidence relating the IC to motor behavior shows that glutamatergic and GABAergic mechanisms in the IC exert influence on systemic haloperidol-induced catalepsy. There is substantial evidence supporting a role played by the endocannabinoid system as a modulator of the glutamatergic neurotransmission, as well as the dopaminergic activity in the basal nuclei and therefore it may be considered as a potential pharmacological target for the treatment of movement disorders. The present study evaluated if the endocannabinoid system in the IC plays a role in the elaboration of systemic haloperidol-induced catalepsy. Male Wistar rats received intracollicular microinjection of either the endogenous cannabinoid anandamide (AEA) at different concentrations (5, 50 or 100pmol/0.2μl), the CB1 cannabinoid receptor antagonist AM251 at 50, 100 or 200pmol/0.2μl or vehicle, followed by intraperitoneal (IP) administration of either haloperidol at 0.5 or 1mg/kg or physiological saline. Systemic injection of haloperidol at both doses (0.5 or 1mg/kg, IP) produced a cataleptic state, compared to vehicle/physiological saline-treated group, lasting 30 and 50min after systemic administration of the dopaminergic receptors non-selective antagonist. The midbrain microinjection of AEA at 50pmol/0.2μl increased the latency for stepping down from the horizontal bar after systemic administration of haloperidol. Moreover, the intracollicular administration of AEA at 50pmol/0.2μl was able to increase the duration of catalepsy as compared to AEA at 100pmol/0.2-μl-treated group. Intracollicular pretreatment with AM251 at the intermediate concentration (100pmol/0.2μl) was able to decrease the duration of catalepsy after systemic administration of haloperidol. However

  14. Cannabinoid receptor-specific mechanisms to alleviate pain in sickle cell anemia via inhibition of mast cell activation and neurogenic inflammation

    PubMed Central

    Vincent, Lucile; Vang, Derek; Nguyen, Julia; Benson, Barbara; Lei, Jianxun; Gupta, Kalpna

    2016-01-01

    Sickle cell anemia is a manifestation of a single point mutation in hemoglobin, but inflammation and pain are the insignia of this disease which can start in infancy and continue throughout life. Earlier studies showed that mast cell activation contributes to neurogenic inflammation and pain in sickle mice. Morphine is the common analgesic treatment but also remains a major challenge due to its side effects and ability to activate mast cells. We, therefore, examined cannabinoid receptor-specific mechanisms to mitigate mast cell activation, neurogenic inflammation and hyperalgesia, using HbSS-BERK sickle and cannabinoid receptor-2-deleted sickle mice. We show that cannabinoids mitigate mast cell activation, inflammation and neurogenic inflammation in sickle mice via both cannabinoid receptors 1 and 2. Thus, cannabinoids influence systemic and neural mechanisms, ameliorating the disease pathobiology and hyperalgesia in sickle mice. This study provides ‘proof of principle’ for the potential of cannabinoid/cannabinoid receptor-based therapeutics to treat several manifestations of sickle cell anemia. PMID:26703965

  15. Sex-specific alterations in hippocampal cannabinoid 1 receptor expression following adolescent delta-9-tetrahydrocannabinol treatment in the rat.

    PubMed

    Silva, Lindsay; Harte-Hargrove, Lauren; Izenwasser, Sari; Frank, Ashley; Wade, Dean; Dow-Edwards, Diana

    2015-08-18

    Marijuana use by adolescents has been on the rise since the early 1990s. With recent legalization and decriminalization acts passed, cannabinoid exposure in adolescents will undoubtedly increase. Human studies are limited in their ability to examine underlying changes in brain biochemistry making rodent models valuable. Studies in adult and adolescent animals show region and sex specific downregulation of the cannabinoid 1 (CB1) receptor following chronic cannabinoid treatment. However, although sex-dependent changes in behavior have been observed during the drug abstinence period following adolescent cannabinoid exposure, little is known about CB1 receptor expression during this critical time. In order to characterize CB1 receptor expression following chronic adolescent Δ-9-tetrahydrocannabinol (THC) exposure, we used [(3)H] CP55,940 binding to assess CB1 receptor expression in the dentate gyrus and areas CA1, CA2, and CA3 of the hippocampus in both male and female adolescent rats at both 24h and 2 weeks post chronic THC treatment. Consistent with other reported findings, we found downregulation of the CB1 receptor in the hippocampal formation at 24h post treatment. While this downregulation persisted in both sexes following two weeks of abstinence in the CA2 region, in females, this downregulation also persisted in areas CA1 and CA3. Expression in the dentate gyrus returned to the normal range by two weeks. These data suggest that selective regions of the hippocampus show persistent reductions in CB1 receptor expression and that these reductions are more widespread in female compared to male adolescents.

  16. Sex-Specific Alterations in Hippocampal Cannabinoid 1 Receptor Expression Following Adolescent Delta-9-Tetrahydrocannabinol Treatment in the Rat

    PubMed Central

    Silva, Lindsay; Harte-Hargrove, Lauren; Izenwasser, Sari; Frank, Ashley; Wade, Dean; Dow-Edwards, Diana

    2015-01-01

    Marijuana use by adolescents has been on the rise since the early 1990’s. With recent legalization and decriminalization acts passed, cannabinoid exposure in adolescents will undoubtedly increase. Human studies are limited in their ability to examine underlying changes in brain biochemistry making rodent models valuable. Studies in adult and adolescent animals show region and sex specific downregulation of the cannabinoid 1 (CB1) receptor following chronic cannabinoid treatment. However, although sex-dependent changes in behavior have been observed during the drug abstinence period following adolescent cannabinoid exposure, little is known about CB1 receptor expression during this critical time. In order to characterize CB1 receptor expression following chronic adolescent Δ-9-tetrahydrocannabinol (THC) exposure, we used [3H]CP55,940 binding to assess CB1 receptor expression in the dentate gyrus and areas CA1, CA2, and CA3 of the hippocampus in both male and female adolescent rats at both 24 hours and 2 weeks post chronic THC treatment. Consistent with other reported findings, we found downregulation of the CB1 receptor in the hippocampal formation at 24 hours post treatment. While this downregulation persisted in both sexes following two weeks of abstinence in the CA2 region, in females, this downregulation also persisted in areas CA1 and CA3. Expression in the dentate gyrus returned to the normal range by two weeks. These data suggest that selective regions of the hippocampus show persistent reductions in CB1 receptor expression and that these reductions are more widespread in female compared to male adolescents. PMID:26118897

  17. FLUORINATED CANNABINOID CB2 RECEPTOR LIGANDS: SYNTHESIS AND IN VITRO BINDING CHARACTERISTICS OF 2-OXOQUINOLINE DERIVATIVES

    PubMed Central

    Turkman, Nashaat; Shavrin, Aleksander; Ivanov, Roman A.; Rabinovich, Brian; Volgin, Andrei; Gelovani, Juri G.; Alauddin, Mian M.

    2011-01-01

    Cannabinoid receptor 2 (CB2) plays an important role in human physiology and the pathophysiology of different diseases, including neuroinflammation, neurodegeneration, and cancer. Several classes of CB2 receptor ligands, including 2-oxoquinoline derivatives, have been previously reported. We report the synthesis and results of in vitro receptor binding of a focused library of new fluorinated 2-oxoquinoline CB2 ligands. Twelve compounds, 13-16 18, 19, 21-24, 27, and 28 were synthesized in good yields in multiple steps. Human U87 glioma cells expressing either hCB1 (control) or hCB2 were generated via lentiviral transduction. In vitro competitive binding assay was performed using [3H]CP-55,940 in U87hCB1 and U87hCB2 cells. Inhibition constant (Ki) values of compounds 13, 14, 15, 16, 18, 19, 21, 22, 23, 24, 27, and 28 for CB2 were >10000, 2.8, 5.0, 2.4, 22, 0.8, 1.4, >10000, 486, 58, 620, and 2400 nM, respectively, and those for CB1 were >10000 nM. Preliminary in vitro results suggest that six of these compounds may be useful for therapy of neuropathic pain, neuroinflammatory diseases and immune disorders. In addition, compound 19, with its subnanomolar Ki value, could be radiolabeled with 18F and explored for PET imaging of CB2 expression. PMID:21872477

  18. Cannabinoid CB1 receptor as a target for chlorpyrifos oxon and other organophosphorus pesticides.

    PubMed

    Quistad, Gary B; Nomura, Daniel K; Sparks, Susan E; Segall, Yoffi; Casida, John E

    2002-09-05

    Binding of the endocannabinoid anandamide or of Delta(9)-tetrahydrocannabinol to the agonist site of the cannabinoid receptor (CB1) is commonly assayed with [3H]CP 55,940. Potent long-chain alkylfluorophosphonate inhibitors of agonist binding suggest an additional, important and closely-coupled nucleophilic site, possibly undergoing phosphorylation. We find that the CB1 receptor is also sensitive to inhibition in vitro and in vivo by several organophosphorus pesticides and analogs. Binding of [3H]CP 55,940 to mouse brain CB1 receptor in vitro is inhibited 50% by chlorpyrifos oxon at 14 nM, chlorpyrifos methyl oxon at 64 nM and paraoxon, diazoxon and dichlorvos at 1200-4200 nM. Some 15 other organophosphorus pesticides and analogs are less active in vitro. The plant defoliant tribufos inhibits CB1 in vivo, without cholinergic poisoning signs, by 50% at 50 mg/kg intraperitoneally with a recovery half-time of 3-4 days, indicating covalent derivatization. [3H-ethyl]Chlorpyrifos oxon may be suitable for radiolabeling and characterization of this proposed nucleophilic site.

  19. Validating Antibodies to the Cannabinoid CB2 Receptor: Antibody Sensitivity Is Not Evidence of Antibody Specificity.

    PubMed

    Marchalant, Yannick; Brownjohn, Philip W; Bonnet, Amandine; Kleffmann, Torsten; Ashton, John C

    2014-06-01

    Antibody-based methods for the detection and quantification of membrane integral proteins, in particular, the G protein-coupled receptors (GPCRs), have been plagued with issues of primary antibody specificity. In this report, we investigate one of the most commonly utilized commercial antibodies for the cannabinoid CB2 receptor, a GPCR, using immunoblotting in combination with mass spectrometry. In this way, we were able to develop powerful negative and novel positive controls. By doing this, we are able to demonstrate that it is possible for an antibody to be sensitive for a protein of interest-in this case CB2-but still cross-react with other proteins and therefore lack specificity. Specifically, we were able to use western blotting combined with mass spectrometry to unequivocally identify CB2 protein in over-expressing cell lines. This shows that a common practice of validating antibodies with positive controls only is insufficient to ensure antibody reliability. In addition, our work is the first to develop a label-free method of protein detection using mass spectrometry that, with further refinement, could provide unequivocal identification of CB2 receptor protein in native tissues.

  20. Electroacupuncture Inhibition of Hyperalgesia in Rats with Adjuvant Arthritis: Involvement of Cannabinoid Receptor 1 and Dopamine Receptor Subtypes in Striatum

    PubMed Central

    Shou, Yin; Yang, Yang; Xu, Ming-Shu; Zhao, Ying-Qian; Ge, Lin-Bao; Zhang, Bi-Meng

    2013-01-01

    Electroacupuncture (EA) has been regarded as an alternative treatment for inflammatory pain for several decades. However, the molecular mechanisms underlying the antinociceptive effect of EA have not been thoroughly clarified. Previous studies have shown that cannabinoid CB1 receptors are related to pain relief. Accumulating evidence has shown that the CB1 and dopamine systems sometimes interact and may operate synergistically in rat striatum. To our knowledge, dopamine D1/D2 receptors are involved in EA analgesia. In this study, we found that repeated EA at Zusanli (ST36) and Kunlun (BL60) acupoints resulted in marked improvements in thermal hyperalgesia. Both western blot assays and FQ-PCR analysis results showed that the levels of CB1 expression in the repeated-EA group were much higher than those in any other group (P = 0.001). The CB1-selective antagonist AM251 inhibited the effects of repeated EA by attenuating the increases in CB1 expression. The two kinds of dopamine receptors imparted different actions on the EA-induced CB1 upregulation in AA rat model. These results suggested that the strong activation of the CB1 receptor after repeated EA resulted in the concomitant phenomenon of the upregulation of D1 and D2 levels of gene expression. PMID:23762129

  1. Potential of the cannabinoid CB(2) receptor as a pharmacological target against inflammation in Parkinson's disease.

    PubMed

    Gómez-Gálvez, Yolanda; Palomo-Garo, Cristina; Fernández-Ruiz, Javier; García, Concepción

    2016-01-04

    Inflammation is an important pathogenic factor in Parkinson's disease (PD), so that it can contribute to kill dopaminergic neurons of the substantia nigra and to enhance the dopaminergic denervation of the striatum. The cannabinoid type-2 (CB2) receptor has been investigated as a potential anti-inflammatory and neuroprotective target in different neurodegenerative disorders, but still limited evidence has been collected in PD. Here, we show for the first time that CB2 receptors are elevated in microglial cells recruited and activated at lesioned sites in the substantia nigra of PD patients compared to control subjects. Parkinsonian inflammation can be reproduced experimentally in rodents by intrastriatal injections of lipopolysaccharide (LPS) which, through an intense activation of glial elements and peripheral infiltration, provokes a rapid deterioration of the striatum that may extend to the substantia nigra too. Using this experimental model, we recently described a much more intense deterioration of tyrosine hydroxylase (TH)-containing nigral neurons in CB2 receptor-deficient mice compared to wild-type animals, supporting a potential neuroprotective role for this receptor. In the present study, we further explored this issue. First, we found elevated levels of the CB2 receptor measured by qRT-PCR in the striatum and substantia nigra of LPS-lesioned mice, as well as an increase in the immunostaining for this receptor in the LPS-lesioned striatum. Second, we found a significant increase in CD68 immunostaining, which serve to identify activated microglia and also infiltrated peripheral macrophages, in these brain structures in response to LPS insult, which was much more intense in CB2 receptor-deficient mice in the case of the substantia nigra. Next, we observed that the activation of CB2 receptors with a selective agonist (HU-308) reversed LPS-induced elevation of CD68 immunostaining in the striatum and the parallel reduction in TH immunostaining. Lastly, we

  2. Application of HaloTag Technology to Expression and Purification of Cannabinoid Receptor CB2

    PubMed Central

    Locatelli-Hoops, Silvia; Sheen, Fangmin C.; Zoubak, Lioudmila; Gawrisch, Klaus; Yeliseev, Alexei A.

    2013-01-01

    Expression of milligram quantities of functional, stable G protein-coupled receptors (GPCR) for high-resolution structural studies remains a challenging task. The goal of this work was to evaluate the usefulness of the HaloTag system (Promega) for expression and purification of the human cannabinoid receptor CB2, an important target for development of drugs for treatment of immune disorders, inflammation, and pain. Here we investigated expression in Escherichia coli cells of the integral membrane receptor CB2 as a fusion with the 34 kDa HaloTag at N- or C-terminal location, either in the presence or in the absence of the N-terminal maltose-binding protein (MBP). The CB2 was flanked at both ends by the tobacco etch virus (TEV) protease cleavage sites to allow for subsequent removal of expression partners. Expression by induction with either IPTG (in E. coli BL21(DE3) cell cultures) or by auto-induction (in E. coli KRX cells) were compared. While the N-terminal location of the HaloTag resulted in high levels of expression of the fusion CB2, the recombinant receptor was not functional. However, when the HaloTag was placed in the C-terminal location, a fully active receptor was produced irrespective of induction method or bacterial strain used. For purification, the fusion protein was captured onto HaloLink resin in the presence of detergents. Treatment with specific TEV protease released the CB2 upon washing. To our knowledge, this study represents the first example of expression, surface immobilization and purification of a functional GPCR using HaloTag technology. PMID:23470778

  3. Phencyclidine-induced social withdrawal results from deficient stimulation of cannabinoid CB₁ receptors: implications for schizophrenia.

    PubMed

    Seillier, Alexandre; Martinez, Alex A; Giuffrida, Andrea

    2013-08-01

    The neuronal mechanisms underlying social withdrawal, one of the core negative symptoms of schizophrenia, are not well understood. Recent studies suggest an involvement of the endocannabinoid system in the pathophysiology of schizophrenia and, in particular, of negative symptoms. We used biochemical, pharmacological, and behavioral approaches to investigate the role played by the endocannabinoid system in social withdrawal induced by sub-chronic administration of phencyclidine (PCP). Pharmacological enhancement of endocannabinoid levels via systemic administration of URB597, an inhibitor of endocannabinoid degradation, reversed social withdrawal in PCP-treated rats via stimulation of CB1 receptors, but reduced social interaction in control animals through activation of a cannabinoid/vanilloid-sensitive receptor. In addition, the potent CB agonist CP55,940 reversed PCP-induced social withdrawal in a CB₁-dependent manner, whereas pharmacological blockade of CB₁ receptors by either AM251 or SR141716 reduced the time spent in social interaction in control animals. PCP-induced social withdrawal was accompanied by a decrease of anandamide (AEA) levels in the amygdala and prefrontal cortex, and these deficits were reversed by URB597. As CB₁ receptors are predominantly expressed on GABAergic interneurons containing the anxiogenic peptide cholecystokinin (CCK), we also examined whether the PCP-induced social withdrawal resulted from deficient CB₁-mediated modulation of CCK transmission. The selective CCK2 antagonist LY225910 blocked both PCP- and AM251-induced social withdrawal, but not URB597 effect in control rats. Taken together, these findings indicate that AEA-mediated activation of CB₁ receptors is crucial for social interaction, and that PCP-induced social withdrawal results from deficient endocannabinoid transmission.

  4. Heteromultimerization of cannabinoid CB(1) receptor and orexin OX(1) receptor generates a unique complex in which both protomers are regulated by orexin A.

    PubMed

    Ward, Richard J; Pediani, John D; Milligan, Graeme

    2011-10-28

    Agonist-induced internalization was observed for both inducible and constitutively expressed forms of the cannabinoid CB(1) receptor. These were also internalized by the peptide orexin A, which has no direct affinity for the cannabinoid CB(1) receptor, but only when the orexin OX(1) receptor was co-expressed along with the cannabinoid CB(1) receptor. This effect of orexin A was concentration-dependent and blocked by OX(1) receptor antagonists. Moreover, the ability of orexin A to internalize the CB(1) receptor was also blocked by CB(1) receptor antagonists. Remarkably, orexin A was substantially more potent in producing internalization of the CB(1) receptor than in causing internalization of the bulk OX(1) receptor population, and this was true in cells in which the CB(1) receptor was maintained at a constant level, whereas levels of OX(1) could be varied and vice versa. Both co-immunoprecipitation and cell surface, homogenous time-resolved fluorescence resonance energy transfer based on covalent labeling of N-terminal "SNAP" and "CLIP" tags present in the extracellular N-terminal domain of the receptors confirmed the capacity of these two receptors to heteromultimerize. These studies confirm the capacity of the CB(1) and OX(1) receptors to interact directly and demonstrate that this complex has unique regulatory characteristics. The higher potency of the agonist orexin A to regulate the CB(1)-OX(1) heteromer compared with the OX(1)-OX(1) homomer present in the same cells and the effects of CB(1) receptor antagonists on the function of orexin A suggest an interplay between these two systems that may modulate appetite, feeding, and wakefulness.

  5. The roles of cannabinoid and dopamine receptor systems in neural emotional learning circuits: implications for schizophrenia and addiction.

    PubMed

    Laviolette, S R; Grace, A A

    2006-07-01

    Cannabinoids represent one of the most widely used hallucinogenic drugs and induce profound alterations in sensory perception and emotional processing. Similarly, the dopamine (DA) neurotransmitter system is critical for the central processing of emotion and motivation. Functional disturbances in either of these neurotransmitter systems are well-established correlates of the psychopathological symptoms and behavioral manifestations observed in addiction and schizophrenia. Increasing evidence from the anatomical, pharmacological and behavioral neuroscience fields points to complex functional interactions between these receptor systems at the anatomical, pharmacological and neural systems levels. An important question relates to whether these systems act in an orchestrated manner to produce the emotional processing and sensory perception deficits underlying addiction and schizophrenia. This review describes evidence for functional neural interactions between cannabinoid and DA receptor systems and how disturbances in this neural circuitry may underlie the aberrant emotional learning and processing observed in disorders such as addiction and schizophrenia.

  6. Prospects for cannabinoid therapies in basal ganglia disorders

    PubMed Central

    Fernández-Ruiz, Javier; Moreno-Martet, Miguel; Rodríguez-Cueto, Carmen; Palomo-Garo, Cristina; Gómez-Cañas, María; Valdeolivas, Sara; Guaza, Carmen; Romero, Julián; Guzmán, Manuel; Mechoulam, Raphael; Ramos, José A

    2011-01-01

    Cannabinoids are promising medicines to slow down disease progression in neurodegenerative disorders including Parkinson's disease (PD) and Huntington's disease (HD), two of the most important disorders affecting the basal ganglia. Two pharmacological profiles have been proposed for cannabinoids being effective in these disorders. On the one hand, cannabinoids like Δ9-tetrahydrocannabinol or cannabidiol protect nigral or striatal neurons in experimental models of both disorders, in which oxidative injury is a prominent cytotoxic mechanism. This effect could be exerted, at least in part, through mechanisms independent of CB1 and CB2 receptors and involving the control of endogenous antioxidant defences. On the other hand, the activation of CB2 receptors leads to a slower progression of neurodegeneration in both disorders. This effect would be exerted by limiting the toxicity of microglial cells for neurons and, in particular, by reducing the generation of proinflammatory factors. It is important to mention that CB2 receptors have been identified in the healthy brain, mainly in glial elements and, to a lesser extent, in certain subpopulations of neurons, and that they are dramatically up-regulated in response to damaging stimuli, which supports the idea that the cannabinoid system behaves as an endogenous neuroprotective system. This CB2 receptor up-regulation has been found in many neurodegenerative disorders including HD and PD, which supports the beneficial effects found for CB2 receptor agonists in both disorders. In conclusion, the evidence reported so far supports that those cannabinoids having antioxidant properties and/or capability to activate CB2 receptors may represent promising therapeutic agents in HD and PD, thus deserving a prompt clinical evaluation. LINKED ARTICLES This article is part of a themed issue on Cannabinoids in Biology and Medicine. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2011.163.issue-7 PMID:21545415

  7. New ursane triterpenoids from Ficus pandurata and their binding affinity for human cannabinoid and opioid receptors.

    PubMed

    Khedr, Amgad I M; Ibrahim, Sabrin R M; Mohamed, Gamal A; Ahmed, Hany E A; Ahmad, Amany S; Ramadan, Mahmoud A; El-Baky, Atef E Abd; Yamada, Koji; Ross, Samir A

    2016-07-01

    Phytochemical investigation of Ficus pandurata Hance (Moraceae) fruits has led to the isolation of two new triterpenoids, ficupanduratin A [1β-hydroxy-3β-acetoxy-11α-methoxy-urs-12-ene] (11) and ficupanduratin B [21α-hydroxy-3β-acetoxy-11α-methoxy-urs-12-ene] (17), along with 20 known compounds: α-amyrin acetate (1), α-amyrin (2), 3β-acetoxy-20-taraxasten-22-one (3), 3β-acetoxy-11α-methoxy-olean-12-ene (4), 3β-acetoxy-11α-methoxy-12-ursene (5), 11-oxo-α-amyrin acetate (6), 11-oxo-β-amyrin acetate (7), palmitic acid (8), stigmast-4,22-diene-3,6-dione (9), stigmast-4-ene-3,6-dione (10), stigmasterol (12), β-sitosterol (13), stigmast-22-ene-3,6-dione (14), stigmastane-3,6-dione (15), 3β,21β-dihydroxy-11α-methoxy-olean-12-ene (16), 3β-hydroxy-11α-methoxyurs-12-ene (18), 6-hydroxystigmast-4,22-diene-3-one (19), 6-hydroxystigmast-4-ene-3-one (20), 11α,21α-dihydroxy-3β-acetoxy-urs-12-ene (21), and β-sitosterol-3-O-β-D-glucopyranoside (22). Compound 21 is reported for the first time from a natural source. The structures of the 20 compounds were elucidated on the basis of IR, 1D ((1)H and (13)C), 2D ((1)H-(1)H COSY, HSQC, HMBC and NOESY) NMR and MS spectroscopic data, in addition to comparison with literature data. The isolated compounds were evaluated for their anti-microbial, anti-malarial, anti-leishmanial, and cytotoxic activities. In addition, their radioligand displacement affinity on opioid and cannabinoid receptors was assessed. Compounds 4, 11, and 15 exhibited good affinity towards the CB2 receptor, with displacement values of 69.7, 62.5 and 86.5 %, respectively. Furthermore, the binding mode of the active compounds in the active site of the CB2 cannabinoid receptors was investigated through molecular modelling.

  8. Enhanced Functional Activity of the Cannabinoid Type-1 Receptor Mediates Adolescent Behavior

    PubMed Central

    Kasanetz, Fernando; Lynch, Diane L.; Friemel, Chris M.; Lassalle, Olivier; Hurst, Dow P.; Steindel, Frauke; Monory, Krisztina; Schäfer, Carola; Miederer, Isabelle; Leweke, F. Markus; Schreckenberger, Mathias; Lutz, Beat; Reggio, Patricia H.; Manzoni, Olivier J.; Spanagel, Rainer

    2015-01-01

    Adolescence is characterized by drastic behavioral adaptations and comprises a particularly vulnerable period for the emergence of various psychiatric disorders. Growing evidence reveals that the pathophysiology of these disorders might derive from aberrations of normal neurodevelopmental changes in the adolescent brain. Understanding the molecular underpinnings of adolescent behavior is therefore critical for understanding the origin of psychopathology, but the molecular mechanisms that trigger adolescent behavior are unknown. Here, we hypothesize that the cannabinoid type-1 receptor (CB1R) may play a critical role in mediating adolescent behavior because enhanced endocannabinoid (eCB) signaling has been suggested to occur transiently during adolescence. To study enhanced CB1R signaling, we introduced a missense mutation (F238L) into the rat Cnr1 gene that encodes for the CB1R. According to our hypothesis, rats with the F238L mutation (Cnr1F238L) should sustain features of adolescent behavior into adulthood. Gain of function of the mutated receptor was demonstrated by in silico modeling and was verified functionally in a series of biochemical and electrophysiological experiments. Mutant rats exhibit an adolescent-like phenotype during adulthood compared with wild-type littermates, with typical high risk/novelty seeking, increased peer interaction, enhanced impulsivity, and augmented reward sensitivity for drug and nondrug reward. Partial inhibition of CB1R activity in Cnr1F238L mutant rats normalized behavior and led to a wild-type phenotype. We conclude that the activity state and functionality of the CB1R is critical for mediating adolescent behavior. These findings implicate the eCB system as an important research target for the neuropathology of adolescent-onset mental health disorders. SIGNIFICANCE STATEMENT We present the first rodent model with a gain-of-function mutation in the cannabinoid type-1 receptor (CB1R). Adult mutant rats exhibit an adolescent

  9. Desensitization of transient receptor potential ankyrin 1 (TRPA1) by the TRP vanilloid 1-selective cannabinoid arachidonoyl-2 chloroethanolamine.

    PubMed

    Ruparel, Nikita B; Patwardhan, Amol M; Akopian, Armen N; Hargreaves, Kenneth M

    2011-07-01

    Recent studies on cannabinoid-induced analgesia implicate certain transient receptor potential (TRP) channels as a therapeutic target along with metabotropic cannabinoid receptors. Although TRP ankyrin 1 (TRPA1)-selective cannabinoids, such as (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo-[1,2,3-d,e]-1,4-benzoxazin-6-yl]-1-naphthalenyl-methanone (WIN55,212), are effective at desensitizing TRPA1 and TRP vanilloid 1 (TRPV1), there is a gap in knowledge in understanding the opposite situation, namely whether TRPV1-selective cannabinoids desensitize TRPA1. We selected the TRPV1-specific synthetic cannabinoid, arachidonoyl-2 chloroethanolamine (ACEA), to study peripheral antihyperalgesic properties because ACEA is known to activate TRPV1. Hence, we used in vitro as well as in vivo assays to evaluate the following: 1) the effects of ACEA on the TRPA1-selective agonist, mustard oil (MO), for calcitonin gene-related peptide (CGRP) release from rat hindpaw skin in vitro; 2) the effects of a peripherally selective dose of ACEA on MO-induced nocifensive behavior in vivo; and 3) the effects of five ACEA-insensitive TRPV1 mutations on ACEA-inhibition of MO-evoked calcium accumulation using a Chinese hamster ovary cell expression system. Our results demonstrate that 1) ACEA significantly attenuated (∼40%) MO-evoked CGRP release from rat hindpaw skin, and this effect was not antagonized by the TRPV1 antagonist, capsazepine; 2) ACEA significantly inhibited (∼40%) MO-induced nocifensive behavior in wild-type mice but not in TRPV1 knockout mice; and 3) all TRPV1 mutations insensitive to ACEA lacked the ability to inhibit MO-evoked calcium accumulation in Chinese hamster ovary cells transfected with TRPV1 and TRPA1. Taken together, the results indicate that a TRPV1-selective cannabinoid, ACEA, inhibits MO-evoked responses via a TRPV1-dependent mechanism. This study strengthens the hypothesis that cannabinoids mediate their peripheral analgesic properties, at least

  10. The cannabinoid CB2 receptor-specific agonist AM1241 increases pentylenetetrazole-induced seizure severity in Wistar rats.

    PubMed

    de Carvalho, Cristiane R; Hoeller, Alexandre A; Franco, Pedro L C; Martini, Athos P S; Soares, Flávia M S; Lin, Katia; Prediger, Rui D; Whalley, Benjamin J; Walz, Roger

    2016-11-01

    The potential efficacy of cannabinoid receptor ligands for the treatment of epilepsy remains controversial; cannabis components that act via cannabinoid type 1 (CB1) receptors produce anticonvulsant effects in animal models despite treatment with the CB receptor agonist reliably inducing convulsions in various species. Moreover, the potential role of cannabinoid receptor type 2 (CB2) to modulate seizures remains under-investigated. This study assessed the effects of the selective CB2 receptor agonist, AM1241, on pentylenetetrazole (PTZ)-induced seizures in rats. A stereotactically placed guide cannula was surgically implanted into the right lateral ventricle in adult Wistar rats which, 5-6days later, received an acute intracerebroventricular (i.c.v.) microinfusion of AM1241 (0.01, 1 or 10μg/2μl or vehicle) 5min before intraperitoneal (i.p.) injection of PTZ (70mg/kg). Rats were observed for 30min and the seizure severity behavior measured using a modified Racine's scale. Additional groups of rats were pretreated with a single low dose of the selective CB2 receptor antagonist, AM630 (dose 1mg/kg; i.p.), or vehicle, 30min prior to i.c.v. microinfusion of AM1241 (1μg/2μl). AM1241 administration significantly increased tonic-clonic seizure incidence and severity while also decreasing the onset of generalized seizures (AM1241 1 and 10μg/2μl). Pretreatment with AM630 prevented the proconvulsant effects of AM1241. This study shows, for the first time, that selective activation of CB2 receptors can increase generalized seizure susceptibility and suggests that pathological hyperexcitability phenomena can be differentially regulated by targeting CB1 and CB2 receptors.

  11. Genetic background modifies the effects of type 2 cannabinoid receptor deficiency on bone mass and bone turnover.

    PubMed

    Sophocleous, Antonia; Idris, Aymen I; Ralston, Stuart H

    2014-03-01

    Cannabinoid receptors and their ligands play significant roles in regulating bone metabolism. Previous studies of type 1 cannabinoid receptor-deficient mice have shown that genetic background influences the skeletal phenotype. Here, we investigated the effects of genetic background on the skeletal phenotype of mice with type 2 cannabinoid receptor deficiency (Cnr2 (-/-)). We studied Cnr2 (-/-) mice on a CD1 background and compared the findings with those previously reported in Cnr2 (-/-) C57BL/6 mice. Young female Cnr2 (-/-) CD1 mice had low bone turnover and high trabecular bone mass compared with wild-type (WT), contrasting with the situation in Cnr2 (-/-) C57BL/6 mice where trabecular bone mass has been reported to be similar to WT. The Cnr2 (-/-) CD1 mice lost more trabecular bone at the tibia with age than WT due to reduced bone formation, and at 12 months there was no difference in trabecular bone volume between genotypes. This differs from the phenotype previously reported in C57BL/6 Cnr2 (-/-) mice, where bone turnover is increased and bone mass reduced with age. There were no substantial differences in skeletal phenotype between Cnr2 (-/-) and WT in male mice. Cortical bone phenotype was similar in Cnr2 (-/-) and WT mice of both genders. Deficiency of Cnr2 has site- and gender-specific effects on the skeleton, mainly affecting trabecular bone, which are influenced by genetic differences between mouse strains. Further evaluation of the pathways responsible might yield new insights into the mechanisms by which cannabinoid receptors regulate bone metabolism.

  12. Methamphetamine-seeking behavior is due to inhibition of nicotinic cholinergic transmission by activation of cannabinoid CB1 receptors.

    PubMed

    Hiranita, Takato; Nawata, Yoko; Sakimura, Katsuya; Yamamoto, Tsuneyuki

    2008-12-01

    We previously reported the involvement of cannabinoid CB1 receptors (CB1Rs) and nicotinic acetylcholine receptors (nAChRs) in the reinstatement of methamphetamine (MAP)-seeking behavior (lever-pressing response for MAP reinforcement under saline infusion). The present study examined whether the reinstatement involves interactions between these receptors. Rats were trained to self-administer MAP with a light and tone (MAP-associated cues). Then, extinction sessions under saline infusion without cues were conducted. After that, a reinstatement tests were conducted by either presenting the cues or a MAP-priming injection. Systemic and intracranial administration of HU210, a cannabinoid CB1R agonist, into the nucleus accumbens core (NAC) and prelimbic cortex (PrC) reinstated MAP-seeking behavior. The reinstatement caused by the systemic HU210 treatment was attenuated by intracranial administration of AM251, a cannabinoid CB1R antagonist, into each region mentioned above. Meanwhile, reinstatement induced by the MAP-associated cues and MAP-priming injection was also attenuated by intracranial administration of AM251 in each region. In these regions, the attenuating effects of AM251 on the reinstatement induced by each stimulus were blocked by the intracranial administration of mecamylamine, a non-selective nAChR antagonist, but not by scopolamine, a muscarinic ACh receptor (mAChR) antagonist. Furthermore, the intracranial administration of DHbetaE, an alpha4beta2 nAChR antagonist, but not MLA, an alpha7 nAChR antagonist, into each region blocked the AM251-induced attenuation of the reinstatement. These findings suggest that relapses to MAP-seeking behavior may be due to two steps, first inhibition of ACh transmission by the activation of cannabinoid CB1Rs and then the inactivation of alpha4beta2 nAChRs.

  13. Cannabinoid CB1 receptor antagonists as potential pharmacotherapies for drug abuse disorders.

    PubMed

    Beardsley, Patrick M; Thomas, Brian F; McMahon, Lance R

    2009-04-01

    Since the discovery of the cannabinoid CB1 receptor (CB1R) in 1988, and subsequently of the CB2 receptor (CB2R) in 1993, there has been an exponential growth of research investigating the functions of the endocannabinoid system. The roles of CB1Rs have been of particular interest to psychiatry because of their selective presence within the CNS and because of their association with brain-reward circuits involving mesocorticolimbic dopamine systems. One potential role that has become of considerable focus is the ability of CB1Rs to modulate the effects of the drugs of abuse. Many drugs of abuse elevate dopamine levels, and the ability of CB1R antagonists or inverse agonists to modulate these elevations has suggested their potential application as pharmacotherapies for treating drug abuse disorders. With the identification of the selective CB1R antagonist, rimonabant, in 1994, and subsequently of other CB1R antagonists, there has been a rapid expansion of research investigating their ability to modulate the effects of the drugs of abuse. This review highlights some of the preclinical and clinical studies that have examined the effects of CB1R antagonists under conditions potentially predictive of their therapeutic efficacy as treatments for drug abuse disorders.

  14. Preclinical evaluation of SMM-189, a cannabinoid receptor 2-specific inverse agonist.

    PubMed

    Presley, Chaela; Abidi, Ammaar; Suryawanshi, Satyendra; Mustafa, Suni; Meibohm, Bernd; Moore, Bob M

    2015-08-01

    Cannabinoid receptor 2 agonists and inverse agonists are emerging as new therapeutic options for a spectrum of autoimmune-related disease. Of particular interest, is the ability of CB2 ligands to regulate microglia function in neurodegenerative diseases and traumatic brain injury. We have previously reported the receptor affinity of 3',5'-dichloro-2,6-dihydroxy-biphenyl-4-yl)-phenyl-methanone (SMM-189) and the characterization of the beneficial effects of SMM-189 in the mouse model of mild traumatic brain injury. Herein, we report the further characterization of SMM-189 as a potent and selective CB2 inverse agonist, which acts as a noncompetitive inhibitor of CP 55,940. The ability of SMM-189 to regulate microglial activation, in terms of chemokine expression and cell morphology, has been determined. Finally, we have determined that SMM-189 possesses acceptable biopharmaceutical properties indicating that the triaryl class of CB2 inverse agonists are viable compounds for continued preclinical development for the treatment of neurodegenerative disorders and traumatic brain injury.

  15. Simultaneous Activation of Induced Heterodimerization between CXCR4 Chemokine Receptor and Cannabinoid Receptor 2 (CB2) Reveals a Mechanism for Regulation of Tumor Progression.

    PubMed

    Coke, Christopher J; Scarlett, Kisha A; Chetram, Mahandranauth A; Jones, Kia J; Sandifer, Brittney J; Davis, Ahriea S; Marcus, Adam I; Hinton, Cimona V

    2016-05-06

    The G-protein-coupled chemokine receptor CXCR4 generates signals that lead to cell migration, cell proliferation, and other survival mechanisms that result in the metastatic spread of primary tumor cells to distal organs. Numerous studies have demonstrated that CXCR4 can form homodimers or can heterodimerize with other G-protein-coupled receptors to form receptor complexes that can amplify or decrease the signaling capacity of each individual receptor. Using biophysical and biochemical approaches, we found that CXCR4 can form an induced heterodimer with cannabinoid receptor 2 (CB2) in human breast and prostate cancer cells. Simultaneous, agonist-dependent activation of CXCR4 and CB2 resulted in reduced CXCR4-mediated expression of phosphorylated ERK1/2 and ultimately reduced cancer cell functions such as calcium mobilization and cellular chemotaxis. Given that treatment with cannabinoids has been shown to reduce invasiveness of cancer cells as well as CXCR4-mediated migration of immune cells, it is plausible that CXCR4 signaling can be silenced through a physical heterodimeric association with CB2, thereby inhibiting subsequent functions of CXCR4. Taken together, the data illustrate a mechanism by which the cannabinoid system can negatively modulate CXCR4 receptor function and perhaps tumor progression.

  16. Cannabinoid CB1 receptor antagonist rimonabant disrupts nicotine reward-associated memory in rats.

    PubMed

    Fang, Qin; Li, Fang-Qiong; Li, Yan-Qin; Xue, Yan-Xue; He, Ying-Ying; Liu, Jian-Feng; Lu, Lin; Wang, Ji-Shi

    2011-10-01

    Exposure to cues previously associated with drug intake leads to relapse by activating previously acquired memories. Based on previous findings, in which cannabinoid CB(1) receptors were found to be critically involved in specific aspects of learning and memory, we investigated the role of CB(1) receptors in nicotine reward memory using a rat conditioned place preference (CPP) model. In Experiment 1, rats were trained for CPP with alternating injections of nicotine (0.5mg/kg, s.c.) and saline to acquire the nicotine-conditioned memory. To examine the effects of rimonabant on the reconsolidation of nicotine reward memory, rats were administered rimonabant (0, 0.3, and 3.0mg/kg, i.p.) immediately after reexposure to the drug-paired context. In Experiment 2, rats were trained for CPP similarly to Experiment 1. To examine the effects of rimonabant on the reinstatement of nicotine reward memory, rimonabant (0, 0.3, and 3.0mg/kg, i.p.) was administered before the test of nicotine-induced CPP reinstatement. In Experiment 3, to evaluate whether rimonabant itself produces a reward memory, rats were trained for CPP with alternating injections of different doses of rimonabant (0, 0.3, and 3.0mg/kg) and saline. Rimonabant at a dose of 3.0mg/kg significantly disrupted the reconsolidation of nicotine memory and significantly blocked the reinstatement of nicotine-induced CPP. However, rimonabant itself did not produce CPP. These findings provide clear evidence that CB(1) receptors play a role in nicotine reward memory, suggesting that CB(1) receptor antagonists may be a potential target for managing nicotine addiction.

  17. Bone Cell-autonomous Contribution of Type 2 Cannabinoid Receptor to Breast Cancer-induced Osteolysis.

    PubMed

    Sophocleous, Antonia; Marino, Silvia; Logan, John G; Mollat, Patrick; Ralston, Stuart H; Idris, Aymen I

    2015-09-04

    The cannabinoid type 2 receptor (CB2) has previously been implicated as a regulator of tumor growth, bone remodeling, and bone pain. However, very little is known about the role of the skeletal CB2 receptor in the regulation of osteoblasts and osteoclasts changes associated with breast cancer. Here we found that the CB2-selective agonists HU308 and JWH133 reduced the viability of a variety of parental and bone-tropic human and mouse breast cancer cells at high micromolar concentrations. Under conditions in which these ligands are used at the nanomolar range, HU308 and JWH133 enhanced human and mouse breast cancer cell-induced osteoclastogenesis and exacerbated osteolysis, and these effects were attenuated in cultures obtained from CB2-deficient mice or in the presence of a CB2 receptor blocker. HU308 and JWH133 had no effects on osteoblast growth or differentiation in the presence of conditioned medium from breast cancer cells, but under these circumstances both agents enhanced parathyroid hormone-induced osteoblast differentiation and the ability to support osteoclast formation. Mechanistic studies in osteoclast precursors and osteoblasts showed that JWH133 and HU308 induced PI3K/AKT activity in a CB2-dependent manner, and these effects were enhanced in the presence of osteolytic and osteoblastic factors such as RANKL (receptor activator of NFκB ligand) and parathyroid hormone. When combined with published work, these findings suggest that breast cancer and bone cells exhibit differential responses to treatment with CB2 ligands depending upon cell type and concentration used. We, therefore, conclude that both CB2-selective activation and antagonism have potential efficacy in cancer-associated bone disease, but further studies are warranted and ongoing.

  18. Bone Cell-autonomous Contribution of Type 2 Cannabinoid Receptor to Breast Cancer-induced Osteolysis*

    PubMed Central

    Sophocleous, Antonia; Marino, Silvia; Logan, John G.; Mollat, Patrick; Ralston, Stuart H.; Idris, Aymen I.

    2015-01-01

    The cannabinoid type 2 receptor (CB2) has previously been implicated as a regulator of tumor growth, bone remodeling, and bone pain. However, very little is known about the role of the skeletal CB2 receptor in the regulation of osteoblasts and osteoclasts changes associated with breast cancer. Here we found that the CB2-selective agonists HU308 and JWH133 reduced the viability of a variety of parental and bone-tropic human and mouse breast cancer cells at high micromolar concentrations. Under conditions in which these ligands are used at the nanomolar range, HU308 and JWH133 enhanced human and mouse breast cancer cell-induced osteoclastogenesis and exacerbated osteolysis, and these effects were attenuated in cultures obtained from CB2-deficient mice or in the presence of a CB2 receptor blocker. HU308 and JWH133 had no effects on osteoblast growth or differentiation in the presence of conditioned medium from breast cancer cells, but under these circumstances both agents enhanced parathyroid hormone-induced osteoblast differentiation and the ability to support osteoclast formation. Mechanistic studies in osteoclast precursors and osteoblasts showed that JWH133 and HU308 induced PI3K/AKT activity in a CB2-dependent manner, and these effects were enhanced in the presence of osteolytic and osteoblastic factors such as RANKL (receptor activator of NFκB ligand) and parathyroid hormone. When combined with published work, these findings suggest that breast cancer and bone cells exhibit differential responses to treatment with CB2 ligands depending upon cell type and concentration used. We, therefore, conclude that both CB2-selective activation and antagonism have potential efficacy in cancer-associated bone disease, but further studies are warranted and ongoing. PMID:26195631

  19. Prevention of Paclitaxel-Induced Neuropathy Through Activation of the Central Cannabinoid Type 2 Receptor System

    PubMed Central

    Naguib, Mohamed; Xu, Jijun J.; Diaz, Philippe; Brown, David L.; Cogdell, David; Bie, Bihua; Hu, Jianhua; Craig, Suzanne; Hittelman, Walter N.

    2012-01-01

    Background Peripheral neuropathy is a major dose-limiting toxicity of chemotherapy, especially after multiple courses of paclitaxel. The development of paclitaxel-induced neuropathy is associated with the activation of microglia followed by the activation and proliferation of astrocytes, and the expression and release of proinflammatory cytokines in the spinal dorsal horn. Cannabinoid type 2 (CB2) receptors are expressed in the microglia in neurodegenerative disease models. Methods To explore the potential of CB2 agonists for preventing paclitaxel-induced neuropathy, we designed and synthesized a novel CB2-selective agonist, namely MDA7. The effect of MDA7 in preventing paclitaxel-induced allodynia was assessed in rats and in CB2+/+ and CB2–/– mice. We hypothesize that the CB2 receptor functions in a negative-feedback loop and that early MDA7 administration can blunt the neuroinflammatory response to paclitaxel and prevent mechanical allodynia through interference with specific signaling pathways. Results We found that MDA7 prevents paclitaxel-induced mechanical allodynia in rats and mice in a dose- and time-dependent manner without compromising paclitaxel's antineoplastic effect. MDA7's neuroprotective effect was absent in CB2-/- mice and was blocked by CB2 antagonists, suggesting that MDA7's action directly involves CB2 receptor activation. MDA7 treatment was found to interfere with early events in the paclitaxel-induced neuroinflammatory response as evidenced by relatively reduced Toll-like receptor and CB2 expression in the lumbar spinal cord, reduced levels of extracellular signal regulated kinase 1/2 activity, reduced numbers of activated microglia and astrocytes, and reduced secretion of proinflammatory mediators in vivo and in in vitro models. Conclusions Our findings suggest an innovative therapeutic approach to prevent chemotherapy-induced neuropathy and may permit more aggressive use of active chemotherapeutic regimens with reduced long-term sequelae

  20. Pre-synaptic adenosine A2A receptors control cannabinoid CB1 receptor-mediated inhibition of striatal glutamatergic neurotransmission.

    PubMed

    Martire, Alberto; Tebano, Maria Teresa; Chiodi, Valentina; Ferreira, Samira G; Cunha, Rodrigo A; Köfalvi, Attila; Popoli, Patrizia

    2011-01-01

    An interaction between adenosine A(2A) receptors (A(2A) Rs) and cannabinoid CB(1) receptors (CB(1) Rs) has been consistently reported to occur in the striatum, although the precise mechanisms are not completely understood. As both receptors control striatal glutamatergic transmission, we now probed the putative interaction between pre-synaptic CB(1) R and A(2A) R in the striatum. In extracellular field potentials recordings in corticostriatal slices from Wistar rats, A(2A) R activation by CGS21680 inhibited CB(1) R-mediated effects (depression of synaptic response and increase in paired-pulse facilitation). Moreover, in superfused rat striatal nerve terminals, A(2A) R activation prevented, while A(2A) R inhibition facilitated, the CB(1) R-mediated inhibition of 4-aminopyridine-evoked glutamate release. In summary, the present study provides converging neurochemical and electrophysiological support for the occurrence of a tight control of CB(1) R function by A(2A) Rs in glutamatergic terminals of the striatum. In view of the key role of glutamate to trigger the recruitment of striatal circuits, this pre-synaptic interaction between CB(1) R and A(2A) R may be of relevance for the pathogenesis and the treatment of neuropsychiatric disorders affecting the basal ganglia.

  1. Dual Role of the Second Extracellular Loop of the Cannabinoid Receptor 1: Ligand Binding and Receptor Localization

    PubMed Central

    Ahn, Kwang H.; Bertalovitz, Alexander C.; Mierke, Dale F.

    2009-01-01

    The seven transmembrane α-helices of G protein-coupled receptors (GPCRs) are the hallmark of this superfamily. Intrahelical interactions are critical to receptor assembly and, for the GPCR subclass that binds small molecules, ligand binding. Most research has focused on identifying the ligand binding pocket within the helical bundle, whereas the role of the extracellular loops remains undefined. Molecular modeling of the cannabinoid receptor 1 (CB1) extracellular loop 2 (EC2), however, suggests that EC2 is poised for key interactions. To test this possibility, we employed alanine scanning mutagenesis of CB1 EC2 and identified two distinct regions critical for ligand binding, G protein coupling activity, and receptor trafficking. Receptors with mutations in the N terminus of EC2 (W255A, N256A) were retained in the endoplasmic reticulum and did not bind the agonist (1R,3R,4R)-3-[2-hydroxy-4-(1,1-dimethylheptyl)-phenyl]-4-(3-hydroxypropyl)cyclohexan-1-ol (CP55940) or the inverse agonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide(SR141716A). In contrast, the C terminus of EC2 differentiates agonist and inverse agonist; the P269A, H270A, and I271A receptors exhibited diminished binding for several agonists but bound inverse agonists SR141716A, N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251), and 4-[6-methoxy-2-(4-methoxyphenyl)benzofuran-3-carbonyl]benzonitrile (LY320135) with wild-type receptor affinity. The F268A receptor involving substitution in the Cys-X-X-X-Ar motif, displayed both impaired localization and ligand binding. Other amino acid substitutions at position 268 revealed that highly hydrophobic residues are required to accomplish both functions. It is noteworthy that a F268W receptor was trafficked to the cell surface yet displayed differential binding preference for inverse agonists comparable with the P269A, H270A, and I271A receptors. The findings

  2. CB1 cannabinoid receptor-mediated anandamide signalling reduces the defensive behaviour evoked through GABAA receptor blockade in the dorsomedial division of the ventromedial hypothalamus.

    PubMed

    Dos Anjos-Garcia, Tayllon; Ullah, Farhad; Falconi-Sobrinho, Luiz Luciano; Coimbra, Norberto Cysne

    2017-02-01

    The effects of cannabinoids in brain areas expressing cannabinoid receptors, such as hypothalamic nuclei, are not yet well known. Several studies have demonstrated the role of hypothalamic nuclei in the organisation of behavioural responses induced through innate fear and panic attacks. Panic-prone states are experimentally induced in laboratory animals through a reduction in the GABAergic activity. The aim of the present study was to examine panic-like elaborated defensive behaviour evoked by GABAA receptor blockade with bicuculline (BIC) in the dorsomedial division of the ventromedial hypothalamus (VMHdm). We also aimed to characterise the involvement of endocannabinoids and the CB1 cannabinoid receptor in the modulation of elaborated defence behavioural responses organised with the VMHdm. The guide-cannula was stereotaxicaly implanted in VMHdm and the animals were treated with anandamide (AEA) at different doses, and the effective dose was used after the pre-treatment with the CB1 receptor antagonist AM251, followed by GABAA receptor blockade in VMHdm. The results showed that the intra-hypothalamic administration of AEA at an intermediate dose (5 pmol) attenuated defence responses induced through the intra-VMHdm microinjection of bicuculline (40 ng). This effect, however, was inhibited when applied central microinjection of the CB1 receptor antagonist AM251 in the VMHdm. Moreover, AM251 potentiates de non-oriented escape induced by bicuculline, effect blocked by pre-treatment with the TRPV1 channel antagonist 6-I-CPS. These results indicate that AEA modulates the pro-aversive effects of intra-VMHdm-bicuculline treatment, recruiting CB1 cannabinoid receptors and the TRPV1 channel is involved in the AM251-related potentiation of bicuculline effects on non-oriented escape behaviour.

  3. Cannabinoid 1 receptor knockout mice display cold allodynia, but enhanced recovery from spared-nerve injury-induced mechanical hypersensitivity

    PubMed Central

    Piskoun, Boris; Russo, Lori; Norcini, Monica; Blanck, Thomas; Recio-Pinto, Esperanza

    2016-01-01

    Background The function of the Cannabinoid 1 receptor (CB1R) in the development of neuropathic pain is not clear. Mounting evidence suggest that CB1R expression and activation may contribute to pain. Cannabinoid 1 receptor knockout mice (CB1R−/−) generated on a C57Bl/6 background exhibit hypoalgesia in the hotplate assay and formalin test. These findings suggest that Cannabinoid 1 receptor expression mediates the responses to at least some types of painful stimuli. By using this mouse line, we sought to determine if the lack of Cannabinoid 1 receptor unveils a general hypoalgesic phenotype, including protection against the development of neuropathic pain. The acetone test was used to measure cold sensitivity, the electronic von Frey was used to measure mechanical thresholds before and after spared-nerve injury, and analysis of footprint patterns was conducted to determine if motor function is differentially affected after nerve-injury in mice with varying levels of Cannabinoid 1 receptor. Results At baseline, CB1R−/− mice were hypersensitive in the acetone test, and this phenotype was maintained after spared-nerve injury. Using calcium imaging of lumbar dorsal root ganglion (DRG) cultures, a higher percentage of neurons isolated from CB1R−/− mice were menthol sensitive relative to DRG isolated from wild-type (CB1R+/+) mice. Baseline mechanical thresholds did not differ among genotypes, and mechanical hypersensitivity developed similarly in the first two weeks following spared-nerve injury (SNI). At two weeks post-SNI, CB1R−/− mice recovered significantly from mechanical hypersensitivity, while the CB1R+/+ mice did not. Heterozygous knockouts (CB1R+/−) transiently developed cold allodynia only after injury, but recovered mechanical thresholds to a similar extent as the CB1R−/− mice. Sciatic functional indices, which reflect overall nerve health, and alternation coefficients, which indicate uniformity of strides, were not significantly different

  4. The hallucinogen N,N-dimethyltryptamine (DMT) is an endogenous sigma-1 receptor regulator.

    PubMed

    Fontanilla, Dominique; Johannessen, Molly; Hajipour, Abdol R; Cozzi, Nicholas V; Jackson, Meyer B; Ruoho, Arnold E

    2009-02-13

    The sigma-1 receptor is widely distributed in the central nervous system and periphery. Originally mischaracterized as an opioid receptor, the sigma-1 receptor binds a vast number of synthetic compounds but does not bind opioid peptides; it is currently considered an orphan receptor. The sigma-1 receptor pharmacophore includes an alkylamine core, also found in the endogenous compound N,N-dimethyltryptamine (DMT). DMT acts as a hallucinogen, but its receptor target has been unclear. DMT bound to sigma-1 receptors and inhibited voltage-gated sodium ion (Na+) channels in both native cardiac myocytes and heterologous cells that express sigma-1 receptors. DMT induced hypermobility in wild-type mice but not in sigma-1 receptor knockout mice. These biochemical, physiological, and behavioral experiments indicate that DMT is an endogenous agonist for the sigma-1 receptor.

  5. N-acyl-dopamines: novel synthetic CB(1) cannabinoid-receptor ligands and inhibitors of anandamide inactivation with cannabimimetic activity in vitro and in vivo.

    PubMed Central

    Bisogno, T; Melck, D; Bobrov MYu; Gretskaya, N M; Bezuglov, V V; De Petrocellis, L; Di Marzo, V

    2000-01-01

    We reported previously that synthetic amides of polyunsaturated fatty acids with bioactive amines can result in substances that interact with proteins of the endogenous cannabinoid system (ECS). Here we synthesized a series of N-acyl-dopamines (NADAs) and studied their effects on the anandamide membrane transporter, the anandamide amidohydrolase (fatty acid amide hydrolase, FAAH) and the two cannabinoid receptor subtypes, CB(1) and CB(2). NADAs competitively inhibited FAAH from N18TG2 cells (IC(50)=19-100 microM), as well as the binding of the selective CB(1) receptor ligand, [(3)H]SR141716A, to rat brain membranes (K(i)=250-3900 nM). The arachidonoyl (20:4 omega 6), eicosapentaenoyl (20:5 omega 3), docosapentaenoyl (22:5 omega 3), alpha-linolenoyl (18:3 omega 3) and pinolenoyl (5c,9c,12c 18:3 omega 6) homologues were also found to inhibit the anandamide membrane transporter in RBL-2H3 basophilic leukaemia and C6 glioma cells (IC(50)=17.5-33 microM). NADAs did not inhibit the binding of the CB(1)/CB(2) receptor ligand, [(3)H]WIN55,212-2, to rat spleen membranes (K(i)>10 microM). N-arachidonyl-dopamine (AA-DA) exhibited 40-fold selectivity for CB(1) (K(i)=250 nM) over CB(2) receptors, and N-docosapentaenoyl-dopamine exhibited 4-fold selectivity for the anandamide transporter over FAAH. AA-DA (0.1-10 microM) did not displace D1 and D2 dopamine-receptor high-affinity ligands from rat brain membranes, thus suggesting that this compound has little affinity for these receptors. AA-DA was more potent and efficacious than anandamide as a CB(1) agonist, as assessed by measuring the stimulatory effect on intracellular Ca(2+) mobilization in undifferentiated N18TG2 neuroblastoma cells. This effect of AA-DA was counteracted by the CB(1) antagonist SR141716A. AA-DA behaved as a CB(1) agonist in vivo by inducing hypothermia, hypo-locomotion, catalepsy and analgesia in mice (1-10 mg/kg). Finally, AA-DA potently inhibited (IC(50)=0.25 microM) the proliferation of human breast MCF

  6. Human orexin/hypocretin receptors form constitutive homo- and heteromeric complexes with each other and with human CB{sub 1} cannabinoid receptors

    SciTech Connect

    Jäntti, Maria H.; Mandrika, Ilona; Kukkonen, Jyrki P.

    2014-03-07

    Highlights: • OX{sub 1} and OX{sub 2} orexin and CB{sub 1} cannabinoid receptor dimerization was investigated. • Bioluminescence resonance energy transfer method was used. • All receptors readily formed constitutive homo- and heteromeric complexes. - Abstract: Human OX{sub 1} orexin receptors have been shown to homodimerize and they have also been suggested to heterodimerize with CB{sub 1} cannabinoid receptors. The latter has been suggested to be important for orexin receptor responses and trafficking. In this study, we wanted to assess the ability of the other combinations of receptors to also form similar complexes. Vectors for expression of human OX{sub 1}, OX{sub 2} and CB{sub 1} receptors, C-terminally fused with either Renilla luciferase or GFP{sup 2} green fluorescent protein variant, were generated. The constructs were transiently expressed in Chinese hamster ovary cells, and constitutive dimerization between the receptors was assessed by bioluminescence energy transfer (BRET). Orexin receptor subtypes readily formed homo- and hetero(di)mers, as suggested by significant BRET signals. CB{sub 1} receptors formed homodimers, and they also heterodimerized with both orexin receptors. Interestingly, BRET efficiency was higher for homodimers than for almost all heterodimers. This is likely to be due to the geometry of the interaction; the putatively symmetric dimers may place the C-termini in a more suitable orientation in homomers. Fusion of luciferase to an orexin receptor and GFP{sup 2} to CB{sub 1} produced more effective BRET than the opposite fusions, also suggesting differences in geometry. Similar was seen for the OX{sub 1}–OX{sub 2} interaction. In conclusion, orexin receptors have a significant propensity to make homo- and heterodi-/oligomeric complexes. However, it is unclear whether this affects their signaling. As orexin receptors efficiently signal via endocannabinoid production to CB{sub 1} receptors, dimerization could be an effective way

  7. Targeting Cannabinoid CB2 Receptors in the Central Nervous System. Medicinal Chemistry Approaches with Focus on Neurodegenerative Disorders

    PubMed Central

    Navarro, Gemma; Morales, Paula; Rodríguez-Cueto, Carmen; Fernández-Ruiz, Javier; Jagerovic, Nadine; Franco, Rafael

    2016-01-01

    Endocannabinoids activate two types of specific G-protein-coupled receptors (GPCRs), namely cannabinoid CB1 and CB2. Contrary to the psychotropic actions of agonists of CB1 receptors, and serious side effects of the selective antagonists of this receptor, drugs acting on CB2 receptors appear as promising drugs to combat CNS diseases (Parkinson's disease, Huntington's chorea, cerebellar ataxia, amyotrohic lateral sclerosis). Differential localization of CB2 receptors in neural cell types and upregulation in neuroinflammation are keys to understand the therapeutic potential in inter alia diseases that imply progressive neurodegeneration. Medicinal chemistry approaches are now engaged to develop imaging tools to map receptors in the living human brain, to develop more efficacious agonists, and to investigate the possibility to develop allosteric modulators. PMID:27679556

  8. Cannabinoid CB1 receptor mediates glucocorticoid effects on hormone secretion induced by volume and osmotic changes.

    PubMed

    Ruginsk, S G; Uchoa, E T; Elias, L L K; Antunes-Rodrigues, J

    2012-02-01

    The present study provides the first in vivo evidence that the cannabinoid CB(1) receptor mediates the effects of dexamethasone on hormone release induced by changes in circulating volume and osmolality. Male adult rats were administered with the CB(1) receptor antagonist rimonabant (10 mg/Kg, p.o.), followed or not in 1 hour by dexamethasone (1 mg/Kg, i.p.). Extracellular volume expansion (EVE, 2 mL/100 g of body weight, i.v.) was performed 2 hours after dexamethasone or vehicle treatment using either isotonic (I-EVE, 0.15 mol/L) or hypertonic (H-EVE, 0.30 mol/L) NaCl solution. Five minutes after EVE, animals were decapitated and trunk blood was collected for all plasma measurements. Rimonabant potentiated oxytocin (OT) secretion induced by H-EVE and completely reversed the inhibitory effects of dexamethasone in response to the same stimulus. These data suggest that glucocorticoid modulation of OT release is mediated by the CB(1) receptor. Although dexamethasone did not affect vasopressin (AVP) secretion induced by H-EVE, the administration of rimonabant potentiated AVP release in response to the same stimulus, supporting the hypothesis that the CB(1) receptor regulates AVP secretion independently of glucocorticoid-mediated signalling. Dexamethasone alone did not affect atrial natriuretic peptide (ANP) release stimulated by I-EVE or H-EVE. However, pretreatment with rimonabant potentiated ANP secretion induced by H-EVE, suggesting a possible role for the CB(1) receptor in the control of peripheral factors that modulate cardiovascular function. Rimonabant also reversed the inhibitory effects of dexamethasone on H-EVE-induced corticosterone secretion, reinforcing the hypothesis that the CB(1) receptor may be involved in the negative feedback exerted by glucocorticoids on the activity of the hypothalamic-pituitary-adrenal axis. Collectively, the results of the present study indicate that the CB(1) receptor modulates neurohypophyseal hormone secretion and

  9. Molecular and cellular basis of cannabinoid and opioid interactions.

    PubMed

    Viganò, Daniela; Rubino, Tiziana; Parolaro, Daniela

    2005-06-01

    Cannabinoids and opioids have been shown to possess several similar pharmacological effects, including analgesia and stimulation of brain circuitry that are believed to underlie drug addiction and reward. In recent years, these phenomena have supported the possible existence of functional links in the mechanisms of action of both types of drugs. The present review addresses the recent advances in the study of biochemical and molecular mechanisms underlying opioid and cannabinoid interaction. Several hypothesis have been formulated to explain this cross-modulation including the release of opioid peptides by cannabinoids or endocannabinoids by opioids and interaction at the level of receptor and/or their signal transduction mechanisms. Moreover it is important to consider that the nature of cannabinoid and opioid interaction might differ in the brain circuits mediating reward and in those mediating other pharmacological properties, such as antinociception. While in vitro studies point to the presence of interaction at various steps along the signal transduction pathway, studies in intact animals are frequently contradictory pending on the used species and the adopted protocol. The presence of reciprocal alteration in receptor density and efficiency as well as the modification in opioid/cannabinoid endogenous systems often do not reflect the behavioral results. Further studies are needed since a better knowledge of the opioid-cannabinoid interaction may lead to exciting therapeutic possibilities.

  10. Differential Control of Cocaine Self-Administration by GABAergic and Glutamatergic CB1 Cannabinoid Receptors.

    PubMed

    Martín-García, Elena; Bourgoin, Lucie; Cathala, Adeline; Kasanetz, Fernando; Mondesir, Miguel; Gutiérrez-Rodriguez, Ana; Reguero, Leire; Fiancette, Jean-François; Grandes, Pedro; Spampinato, Umberto; Maldonado, Rafael; Piazza, Pier Vincenzo; Marsicano, Giovanni; Deroche-Gamonet, Véronique

    2016-08-01

    The type 1 cannabinoid receptor (CB1) modulates numerous neurobehavioral processes and is therefore explored as a target for the treatment of several mental and neurological diseases. However, previous studies have investigated CB1 by targeting it globally, regardless of its two main neuronal localizations on glutamatergic and GABAergic neurons. In the context of cocaine addiction this lack of selectivity is critical since glutamatergic and GABAergic neuronal transmission is involved in different aspects of the disease. To determine whether CB1 exerts different control on cocaine seeking according to its two main neuronal localizations, we used mutant mice with deleted CB1 in cortical glutamatergic neurons (Glu-CB1) or in forebrain GABAergic neurons (GABA-CB1). In Glu-CB1, gene deletion concerns the dorsal telencephalon, including neocortex, paleocortex, archicortex, hippocampal formation and the cortical portions of the amygdala. In GABA-CB1, it concerns several cortical and non-cortical areas including the dorsal striatum, nucleus accumbens, thalamic, and hypothalamic nuclei. We tested complementary components of cocaine self-administration, separating the influence of primary and conditioned effects. Mechanisms underlying each phenotype were explored using in vivo microdialysis and ex vivo electrophysiology. We show that CB1 expression in forebrain GABAergic neurons controls mouse sensitivity to cocaine, while CB1 expression in cortical glutamatergic neurons controls associative learning processes. In accordance, in the nucleus accumbens, GABA-CB1 receptors control cocaine-induced dopamine release and Glu-CB1 receptors control AMPAR/NMDAR ratio; a marker of synaptic plasticity. Our findings demonstrate a critical distinction of the altered balance of Glu-CB1 and GABA-CB1 activity that could participate in the vulnerability to cocaine abuse and addiction. Moreover, these novel insights advance our understanding of CB1 neuropathophysiology.

  11. Differential expression of intracellular and extracellular CB(2) cannabinoid receptor protein by human peripheral blood leukocytes.

    PubMed

    Castaneda, Julie T; Harui, Airi; Kiertscher, Sylvia M; Roth, Jeffrey D; Roth, Michael D

    2013-03-01

    mRNA encoding for the CB(2) cannabinoid receptor is expressed by many subsets of human peripheral blood leukocytes (PBL), but little is known about the resulting protein expression and function. Employing clones from the A549 and 293T cell lines that were constructed to express both full-length human CB(2) and GFP, we developed a flow cytometry assay for characterizing CB(2) protein expression. A monoclonal antibody directed against human CB(2) selectively stained the surface of transduced but not parental cell lines. When cells were fixed and permeabilized, imaging flow cytometry identified large stores of intracellular protein. Total cellular staining for CB(2) corresponded closely with the level of GFP expression. When exposed to Δ(9)-tetrahydrocannabinol, CB(2)-expressing cells internalized cell surface CB(2) receptors in a time- and dose-dependent manner. Applying these approaches to human PBL, CB(2) protein was identified on the surface of human B cells but not on T cells or monocytes. In contrast, when PBL were fixed and permeabilized, intracellular CB(2) expression was readily detected in all three subsets by both conventional and imaging flow cytometry. Similar to the protein expression pattern observed in fixed and permeabilized PBL, purified B cells, T cells, and monocytes expressed relatively equal levels of CB(2) mRNA by quantitative real-time RT-PCR. Our findings confirm that human PBL express CB(2) protein but that its distribution is predominantly intracellular with only B cells expressing CB(2) protein at the extracellular membrane. The differential role of intracellular and extracellular CB(2) receptors in mediating ligand signaling and immune function remains to be determined.

  12. Cannabinoids and Reproduction: A Lasting and Intriguing History

    PubMed Central

    Cacciola, Giovanna; Chianese, Rosanna; Chioccarelli, Teresa; Ciaramella, Vincenza; Fasano, Silvia; Pierantoni, Riccardo; Meccariello, Rosaria; Cobellis, Gilda

    2010-01-01

    Starting from an historical overview of lasting Cannabis use over the centuries, we will focus on a description of the cannabinergic system, with a comprehensive analysis of chemical and pharmacological properties of endogenous and synthetic cannabimimetic analogues. The metabolic pathways and the signal transduction mechanisms, activated by cannabinoid receptors stimulation, will also be discussed. In particular, we will point out the action of cannabinoids and endocannabinoids on the different neuronal networks involved in reproductive axis, and locally, on male and female reproductive tracts, by emphasizing the pivotal role played by this system in the control of fertility.

  13. Adolescent exposure to nicotine and/or the cannabinoid agonist CP 55,940 induces gender-dependent long-lasting memory impairments and changes in brain nicotinic and CB(1) cannabinoid receptors.

    PubMed

    Mateos, B; Borcel, E; Loriga, R; Luesu, W; Bini, V; Llorente, R; Castelli, M P; Viveros, M-P

    2011-12-01

    We have analysed the long-term effects of adolescent (postnatal day 28-43) exposure of male and female rats to nicotine (NIC, 1.4 mg/kg/day) and/or the cannabinoid agonist CP 55,940 (CP, 0.4 mg/kg/day) on the following parameters measured in the adulthood: (1) the memory ability evaluated in the object location task (OL) and in the novel object test (NOT); (2) the anxiety-like behaviour in the elevated plus maze; and (3) nicotinic and CB(1) cannabinoid receptors in cingulated cortex and hippocampus. In the OL, all pharmacological treatments induced significant decreases in the DI of females, whereas no significant effects were found among males. In the NOT, NIC-treated females showed a significantly reduced DI, whereas the effect of the cannabinoid agonist (a decrease in the DI) was only significant in males. The anxiety-related behaviour was not changed by any drug. Both, nicotine and cannabinoid treatments induced a long-lasting increase in CB(1) receptor activity (CP-stimulated GTPγS binding) in male rats, and the nicotine treatment also induced a decrease in nicotinic receptor density in the prefrontal cortex of females. The results show gender-dependent harmful effects of both drugs and long-lasting changes in CB(1) and nicotinic receptors.

  14. Functional Genetic Variation of the Cannabinoid Receptor 1 and Cannabis Use Interact on Prefrontal Connectivity and Related Working Memory Behavior

    PubMed Central

    Colizzi, Marco; Fazio, Leonardo; Ferranti, Laura; Porcelli, Annamaria; Masellis, Rita; Marvulli, Daniela; Bonvino, Aurora; Ursini, Gianluca; Blasi, Giuseppe; Bertolino, Alessandro

    2015-01-01

    Cannabinoid signaling is involved in different brain functions and it is mediated by the cannabinoid receptor 1 (CNR1), which is encoded by the CNR1 gene. Previous evidence suggests an association between cognition and cannabis use. The logical interaction between genetically determined cannabinoid signaling and cannabis use has not been determined. Therefore, we investigated whether CNR1 variation predicts CNR1 prefrontal mRNA expression in postmortem prefrontal human tissue. Then, we studied whether functional variation in CNR1 and cannabis exposure interact in modulating prefrontal function and related behavior during working memory processing. Thus, 208 healthy subjects (113 males) were genotyped for the relevant functional SNP and were evaluated for cannabis use by the Cannabis Experience Questionnaire. All individuals performed the 2-back working memory task during functional magnetic resonance imaging. CNR1 rs1406977 was associated with prefrontal mRNA and individuals carrying a G allele had reduced CNR1 prefrontal mRNA levels compared with AA subjects. Moreover, functional connectivity MRI demonstrated that G carriers who were also cannabis users had greater functional connectivity in the left ventrolateral prefrontal cortex and reduced working memory behavioral accuracy during the 2-back task compared with the other groups. Overall, our results indicate that the deleterious effects of cannabis use are more evident on a specific genetic background related to its receptor expression. PMID:25139064

  15. The cannabinoid 1-receptor silent antagonist O-2050 attenuates preference for high-fat diet and activated astrocytes in mice.

    PubMed

    Higuchi, Sei; Irie, Keiichi; Mishima, Shohei; Araki, Maiko; Ohji, Makiko; Shirakawa, Atsunori; Akitake, Yoshiharu; Matsuyama, Kiyoshi; Mishima, Kenji; Mishima, Kenichi; Iwasaki, Katsunori; Fujiwara, Michihiro

    2010-01-01

    Endocannabinoids have been shown to activate reward-related feeding and to promote astrocytic differentiation. We investigated whether high-fat diet (HFD) intake produced a preference for HFD via an endocannabinoid-dependent mechanism. In the conditioned place preference test, the 2-week HFD-intake group showed preference for HFD and had increased expression of a marker for reactive astrocytes, glial fibrillary acid protein (GFAP), in the hypothalamus. The cannabinoid CB(1)-receptor antagonist O-2050 reduced the preference for HFD and expression of GFAP in the hypothalamus. These results suggested that HFD intake led to the development of a preference for HFD via astrocytic CB(1) receptors in the hypothalamus.

  16. Design, synthesis, biological evaluation and binding mode modeling of benzimidazole derivatives targeting the cannabinoid receptor type 1.

    PubMed

    Espinosa-Bustos, Christian; Lagos, Carlos F; Romero-Parra, Javier; Zárate, Ana M; Mella-Raipán, Jaime; Pessoa-Mahana, Hernán; Recabarren-Gajardo, Gonzalo; Iturriaga-Vásquez, Patricio; Tapia, Ricardo A; Pessoa-Mahana, C David

    2015-02-01

    A series of N-acyl-2,5-dimethoxyphenyl-1H-benzimidazoles were designed based on a CoMFA model for cannabinoid receptor type 1 (CB1) ligands. Compounds were synthesized and radioligand binding affinity assays were performed. Eight novel benzimidazoles exhibited affinity for the CB1 receptor in the nanomolar range, and the most promising derivative compound 5 displayed a K(i) value of 1.2 nM when compared to CP55,940. These results confirm our previously reported QSAR model on benzimidazole derivatives, providing new information for the development of small molecules with high CB1 affinity.

  17. Endogenous hallucinogens as ligands of the trace amine receptors: a possible role in sensory perception.

    PubMed

    Wallach, J V

    2009-01-01

    While the endogenous hallucinogens, N,N-dimethyltryptamine, 5-hydroxy-N,N-dimethyl-tryptamine and 5-methoxy-N,N-dimethyltryptamine, have been acknowledged as naturally occurring components of the mammalian body for decades, their biological function remains as elusive now as it was at the time of their discovery. The recent discovery of the trace amine associated receptors and the activity of DMT and other hallucinogenic compounds at these receptor sites leads to the hypothesis that the endogenous hallucinogens act as neurotransmitters of a subclass of these trace amine receptors. Additionally, while activity at the serotonin 5-HT2A receptor has been proposed as being responsible for the hallucinogenic affects of administered hallucinogens, in their natural setting the 5-HT2A receptor may not interact with the endogenous hallucinogens at all. Additionally 5-HT2A agonist activity is unable to account for the visual altering effects of many of the administered hallucinogens; these effects may be mediated by one of the endogenous hallucinogen trace amine receptors rather than the serotonin 5-HT2A receptor. Therefore, activity at the trace amine receptors, in addition to serotonin receptors, may play a large role in the sensory altering effects of administered hallucinogens and the trace amine receptors along with their endogenous hallucinogen ligands may serve an endogenous role in mediating sensory perception in the mammalian central nervous system. Thus the theory proposed states that these compounds act as true endogenous hallucinogenic transmitters acting in regions of the central nervous system involved in sensory perception.

  18. CB2 Cannabinoid Receptors Contribute to Bacterial Invasion and Mortality in Polymicrobial Sepsis

    PubMed Central

    Csóka, Balázs; Németh, Zoltán H.; Mukhopadhyay, Partha; Spolarics, Zoltán; Rajesh, Mohanraj; Federici, Stephanie; Deitch, Edwin A.; Bátkai, Sándor; Pacher, Pál; Haskó, György

    2009-01-01

    Background Sepsis is a major healthcare problem and current estimates suggest that the incidence of sepsis is approximately 750,000 annually. Sepsis is caused by an inability of the immune system to eliminate invading pathogens. It was recently proposed that endogenous mediators produced during sepsis can contribute to the immune dysfunction that is observed in sepsis. Endocannabinoids that are produced excessively in sepsis are potential factors leading to immune dysfunction, because they suppress immune cell function by binding to G-protein-coupled CB2 receptors on immune cells. Here we examined the role of CB2 receptors in regulating the host's response to sepsis. Methods and Findings The role of CB2 receptors was studied by subjecting CB2 receptor wild-type and knockout mice to bacterial sepsis induced by cecal ligation and puncture. We report that CB2 receptor inactivation by knockout decreases sepsis-induced mortality, and bacterial translocation into the bloodstream of septic animals. Furthermore, CB2 receptor inactivation decreases kidney and muscle injury, suppresses splenic nuclear factor (NF)-κB activation, and diminishes the production of IL-10, IL-6 and MIP-2. Finally, CB2 receptor deficiency prevents apoptosis in lymphoid organs and augments the number of CD11b+ and CD19+ cells during CLP. Conclusions Taken together, our results establish for the first time that CB2 receptors are important contributors to septic immune dysfunction and mortality, indicating that CB2 receptors may be therapeutically targeted for the benefit of patients suffering from sepsis. PMID:19641602

  19. Cannabinoid CB2 receptors modulate midbrain dopamine neuronal activity and dopamine-related behavior in mice

    PubMed Central

    Zhang, Hai-Ying; Gao, Ming; Liu, Qing-Rong; Bi, Guo-Hua; Li, Xia; Yang, Hong-Ju; Gardner, Eliot L.; Wu, Jie

    2014-01-01

    Cannabinoid CB2 receptors (CB2Rs) have been recently reported to modulate brain dopamine (DA)-related behaviors; however, the cellular mechanisms underlying these actions are unclear. Here we report that CB2Rs are expressed in ventral tegmental area (VTA) DA neurons and functionally modulate DA neuronal excitability and DA-related behavior. In situ hybridization and immunohistochemical assays detected CB2 mRNA and CB2R immunostaining in VTA DA neurons. Electrophysiological studies demonstrated that activation of CB2Rs by JWH133 or other CB2R agonists inhibited VTA DA neuronal firing in vivo and ex vivo, whereas microinjections of JWH133 into the VTA inhibited cocaine self-administration. Importantly, all of the above findings observed in WT or CB1−/− mice are blocked by CB2R antagonist and absent in CB2−/− mice. These data suggest that CB2R-mediated reduction of VTA DA neuronal activity may underlie JWH133's modulation of DA-regulated behaviors. PMID:25368177

  20. Expression and Functional Relevance of Cannabinoid Receptor 1 in Hodgkin Lymphoma

    PubMed Central

    Benz, Alexander H.; Renné, Christoph; Maronde, Erik; Koch, Marco; Grabiec, Urszula; Kallendrusch, Sonja; Rengstl, Benjamin; Newrzela, Sebastian; Hartmann, Sylvia; Hansmann, Martin-Leo; Dehghani, Faramarz

    2013-01-01

    Background Cannabinoid receptor 1 (CB1) is expressed in certain types of malignancies. An analysis of CB1 expression and function in Hodgkin lymphoma (HL), one of the most frequent lymphomas, was not performed to date. Design and Methods We examined the distribution of CB1 protein in primary cases of HL. Using lymphoma derived cell lines, the role of CB1 signaling on cell survival was investigated. Results A predominant expression of CB1 was found in Hodgkin-Reed-Sternberg cells in a vast majority of classical HL cases. The HL cell lines L428, L540 and KM-H2 showed strong CB1-abundance and displayed a dose-dependent decline of viability under CB1 inhibition with AM251. Further, application of AM251 led to decrease of constitutively active NFκB/p65, a crucial survival factor of HRS-cells, and was followed by elevation of apoptotic markers in HL cells. Conclusions The present study identifies CB1 as a feature of HL, which might serve as a potential selective target in the treatment of Hodgkin lymphoma. PMID:24349109

  1. Cannabinoid- and lysophosphatidylinositol-sensitive receptor GPR55 boosts neurotransmitter release at central synapses.

    PubMed

    Sylantyev, Sergiy; Jensen, Thomas P; Ross, Ruth A; Rusakov, Dmitri A

    2013-03-26

    G protein-coupled receptor (GPR) 55 is sensitive to certain cannabinoids, it is expressed in the brain and, in cell cultures, it triggers mobilization of intracellular Ca(2+). However, the adaptive neurobiological significance of GPR55 remains unknown. Here, we use acute hippocampal slices and combine two-photon excitation Ca(2+) imaging in presynaptic axonal boutons with optical quantal analysis in postsynaptic dendritic spines to find that GPR55 activation transiently increases release probability at individual CA3-CA1 synapses. The underlying mechanism involves Ca(2+) release from presynaptic Ca(2+) stores, whereas postsynaptic stores (activated by spot-uncaging of inositol 1,4,5-trisphosphate) remain unaffected by GPR55 agonists. These effects are abolished by genetic deletion of GPR55 or by the GPR55 antagonist cannabidiol, a constituent of Cannabis sativa. GPR55 shows colocalization with synaptic vesicle protein vesicular glutamate transporter 1 in stratum radiatum. Short-term potentiation of CA3-CA1 transmission after a short train of stimuli reveals a presynaptic, Ca(2+) store-dependent component sensitive to cannabidiol. The underlying cascade involves synthesis of phospholipids, likely in the presynaptic cell, but not the endocannabinoids 2-arachidonoylglycerol or anandamide. Our results thus unveil a signaling role for GPR55 in synaptic circuits of the brain.

  2. Novel Electrophilic and Photoaffinity Covalent Probes for Mapping the Cannabinoid 1 Receptor Allosteric Site(s)

    PubMed Central

    2015-01-01

    Undesirable side effects associated with orthosteric agonists/antagonists of cannabinoid 1 receptor (CB1R), a tractable target for treating several pathologies affecting humans, have greatly limited their translational potential. Recent discovery of CB1R negative allosteric modulators (NAMs) has renewed interest in CB1R by offering a potentially safer therapeutic avenue. To elucidate the CB1R allosteric binding motif and thereby facilitate rational drug discovery, we report the synthesis and biochemical characterization of first covalent ligands designed to bind irreversibly to the CB1R allosteric site. Either an electrophilic or a photoactivatable group was introduced at key positions of two classical CB1R NAMs: Org27569 (1) and PSNCBAM-1 (2). Among these, 20 (GAT100) emerged as the most potent NAM in functional assays, did not exhibit inverse agonism, and behaved as a robust positive allosteric modulator of binding of orthosteric agonist CP55,940. This novel covalent probe can serve as a useful tool for characterizing CB1R allosteric ligand-binding motifs. PMID:26529344

  3. Sex-dependence of anxiety-like behavior in cannabinoid receptor 1 (Cnr1) knockout mice

    PubMed Central

    Bowers, Mallory E.; Ressler, Kerry J.

    2015-01-01

    Epidemiological data suggest women are at increased risk for developing anxiety and depression, although the mechanisms for this sex/gender difference remain incompletely understood. Pre-clinical studies have begun to investigate sex-dependent emotional learning and behavior in rodents, particularly as it relates to psychopathology; however, information about how gonadal hormones interact with the central nervous system is limited. We observe greater anxiety-like behavior in male mice with global knockout of the cannabinoid 1 receptor (Cnr1) compared to male, wild-type controls as measured by percent open arm entries on an elevated plus maze test. A similar increase in anxiety-like behavior, however, is not observed when comparing female Cnr1 knockouts to female wild-type subjects. Although, ovariectomy in female mice did not reverse this effect, both male and female adult mice with normative development were sensitive to Cnr1 antagonist-mediated increases in anxiety-like behavior. Together, these data support an interaction between sex, potentially mediated by gonadal hormones, and the endocannabinoid system at an early stage of development that is critical for establishing adult anxiety-like behavior. PMID:26684509

  4. Bladder cancer cell growth and motility implicate cannabinoid 2 receptor-mediated modifications of sphingolipids metabolism

    PubMed Central

    Bettiga, Arianna; Aureli, Massimo; Colciago, Giorgia; Murdica, Valentina; Moschini, Marco; Lucianò, Roberta; Canals, Daniel; Hannun, Yusuf; Hedlund, Petter; Lavorgna, Giovanni; Colombo, Renzo; Bassi, Rosaria; Samarani, Maura; Montorsi, Francesco; Salonia, Andrea; Benigni, Fabio

    2017-01-01

    The inhibitory effects demonstrated by activation of cannabinoid receptors (CB) on cancer proliferation and migration may also play critical roles in controlling bladder cancer (BC). CB expression on human normal and BC specimens was tested by immunohistochemistry. Human BC cells RT4 and RT112 were challenged with CB agonists and assessed for proliferation, apoptosis, and motility. Cellular sphingolipids (SL) constitution and metabolism were evaluated after metabolic labelling. CB1-2 were detected in BC specimens, but only CB2 was more expressed in the tumour. Both cell lines expressed similar CB2. Exposure to CB2 agonists inhibited BC growth, down-modulated Akt, induced caspase 3-activation and modified SL metabolism. Baseline SL analysis in cell lines showed differences linked to unique migratory behaviours and cytoskeletal re-arrangements. CB2 activation changed the SL composition of more aggressive RT112 cells by reducing (p < 0.01) Gb3 ganglioside (−50 ± 3%) and sphingosine 1-phosphate (S1P, −40 ± 4%), which ended up to reduction in cell motility (−46 ± 5%) with inhibition of p-SRC. CB2-selective antagonists, gene silencing and an inhibitor of SL biosynthesis partially prevented CB2 agonist-induced effects on cell viability and motility. CB2 activation led to ceramide-mediated BC cell apoptosis independently of SL constitutive composition, which instead was modulated by CB2 agonists to reduce cell motility. PMID:28191815

  5. Exercise reduces adipose tissue via cannabinoid receptor type 1 which is regulated by peroxisome proliferator-activated receptor-{delta}

    SciTech Connect

    Yan Zhencheng; Liu Daoyan; Zhang Lili; Shen Chenyi; Ma Qunli; Cao Tingbing; Wang Lijuan; Nie Hai; Zidek, Walter; Tepel, Martin; Zhu Zhiming . E-mail: zhuzm@yahoo.com

    2007-03-09

    Obesity is one major cardiovascular risk factor. We tested effects of endurance exercise on cannabinoid receptor type 1 (CB1) and peroxisome proliferator-activated receptor-{delta} (PPAR-{delta})-dependent pathways in adipose tissue. Male Wistar rats were randomly assigned to standard laboratory chow or a high-fat diet without and with regular endurance exercise. Exercise in rats on high-fat diet significantly reduced visceral fat mass, blood pressure, and adipocyte size (each p < 0.05). Adipocyte hypertrophy induced by high-fat diet was accompanied by increased CB1 expression in adipose tissue, whereas exercise significantly reduced CB1 expression (each p < 0.05). CB1 receptor expression and adipocyte differentiation were directly regulated by PPAR-{delta}. Adipocyte hypertrophy induced by high-fat diet was accompanied by reduced PPAR-{delta}. Furthermore, selective silencing of PPAR-{delta} by RNA interference in 3T3-L1-preadipocyte cells significantly increased CB1 expression from 1.00 {+-} 0.06 (n = 3) to 1.91 {+-} 0.06 (n = 3; p < 0.01) and increased adipocyte differentiation, whereas adenovirus-mediated overexpression of PPAR-{delta} significantly reduced CB1 expression to 0.39 {+-} 0.03 (n = 3; p < 0.01) and reduced adipocyte differentiation. In the presence of the CB1 antagonist rimonabant adipocyte differentiation in stimulated 3T3 L1 preadipocyte cells was significantly reduced. The study indicates that high-fat diet-induced hypertrophy of adipocytes is associated with increased CB1 receptor expression which is directly regulated by PPAR-{delta}. Both CB1 and PPAR-{delta} are intimately involved in therapeutic interventions against a most important cardiovascular risk factor.

  6. Therapeutic potential of cannabinoid medicines.

    PubMed

    Robson, P J

    2014-01-01

    Cannabis was extensively used as a medicine throughout the developed world in the nineteenth century but went into decline early in the twentieth century ahead of its emergence as the most widely used illicit recreational drug later that century. Recent advances in cannabinoid pharmacology alongside the discovery of the endocannabinoid system (ECS) have re-ignited interest in cannabis-based medicines. The ECS has emerged as an important physiological system and plausible target for new medicines. Its receptors and endogenous ligands play a vital modulatory role in diverse functions including immune response, food intake, cognition, emotion, perception, behavioural reinforcement, motor co-ordination, body temperature, wake/sleep cycle, bone formation and resorption, and various aspects of hormonal control. In disease it may act as part of the physiological response or as a component of the underlying pathology. In the forefront of clinical research are the cannabinoids delta-9-tetrahydrocannabinol and cannabidiol, and their contrasting pharmacology will be briefly outlined. The therapeutic potential and possible risks of drugs that inhibit the ECS will also be considered. This paper will then go on to review clinical research exploring the potential of cannabinoid medicines in the following indications: symptomatic relief in multiple sclerosis, chronic neuropathic pain, intractable nausea and vomiting, loss of appetite and weight in the context of cancer or AIDS, psychosis, epilepsy, addiction, and metabolic disorders.

  7. Cannabinoid CB1 receptor recognition of endocannabinoids via the lipid bilayer: molecular dynamics simulations of CB1 transmembrane helix 6 and anandamide in a phospholipid bilayer

    NASA Astrophysics Data System (ADS)

    Lynch, Diane L.; Reggio, Patricia H.

    2006-08-01

    The phospholipid bilayer plays a central role in the lifecycle of the endogenous cannabinoid, N-arachidonoylethanolamine (anandamide, AEA). Therefore, the orientation and location of AEA in the phospholipid bilayer with respect to key membrane associated proteins, is a central issue in understanding the mechanism of endocannabinoid signaling. In this paper, we report a test of the hypothesis that a βXX β motif (formed by beta branching amino acids, V6.43 and I6.46) on the lipid face of the cannabinoid CB1 receptor in its inactive state may serve as an initial CB1 interaction site for AEA. Eight 6 ns NAMD2 molecular dynamics simulations of AEA were conducted in a model system composed of CB1 transmembrane helix 6 (TMH6) in a 1,2-dioleoyl- sn-glycero-3-phosphocholine (DOPC) bilayer. In addition, eight 6 ns NAMD2 molecular dynamics simulations of a low CB1 affinity (20:2, n-6) analog of AEA were conducted in the same model system. AEA was found to exhibit a higher incidence of V6.43/I6.46 groove insertion than did the (20:2, n-6) analog. In certain cases, AEA established a high energy of interaction with TMH6 by first associating with the V6.43/I6.46 groove and then molding itself to the lipid face of TMH6 to establish a hydrogen bonding interaction with the exposed backbone carbonyl of P6.50. Based upon these results, we propose that the formation of this hydrogen bonded AEA/TMH6 complex may be the initial step in CB1 recognition of AEA in the lipid bilayer.

  8. R(+)-methanandamide induces cyclooxygenase-2 expression in human neuroglioma cells via a non-cannabinoid receptor-mediated mechanism.

    PubMed

    Ramer, R; Brune, K; Pahl, A; Hinz, B

    2001-09-07

    Cannabinoids affect prostaglandin (PG) formation in the central nervous system through as yet unidentified mechanisms. Using H4 human neuroglioma cells, the present study investigates the effect of R(+)-methanandamide (metabolically stable analogue of the endocannabinoid anandamide) on the expression of the cyclooxygenase-2 (COX-2) enzyme. Incubation of cells with R(+)-methanandamide was accompanied by concentration-dependent increases in COX-2 mRNA, COX-2 protein, and COX-2-dependent PGE(2) synthesis. Moreover, treatment of cells with R(+)-methanandamide in the presence of interleukin-1beta led to an overadditive induction of COX-2 expression. The stimulatory effect of R(+)-methanandamide on COX-2 expression was mimicked by the structurally unrelated cannabinoid Delta(9)-tetrahydrocannabinol. Stimulation of both COX-2 mRNA expression and subsequent PGE(2) synthesis by R(+)-methanandamide was not affected by the selective CB(1) receptor antagonist AM-251 or the G(i/o) protein inactivator pertussis toxin. Enhancement of COX-2 expression by R(+)-methanandamide was paralleled by time-dependent phosphorylations of p38 mitogen-activated protein kinase (MAPK) and p42/44 MAPK. Consistent with the activation of both kinases, R(+)-methanandamide-induced COX-2 mRNA expression and PGE(2) formation were abrogated in the presence of specific inhibitors of p38 MAPK (SB203580) and p42/44 MAPK activation (PD98059). Together, our results demonstrate that R(+)-methanandamide induces COX-2 expression in human neuroglioma cells via a cannabinoid receptor-independent mechanism involving activation of the MAPK pathway. In conclusion, induction of COX-2 expression may represent a novel mechanism by which cannabinoids mediate PG-dependent effects within the central nervous system.

  9. Repeated administration of a synthetic cannabinoid receptor agonist differentially affects cortical and accumbal neuronal morphology in adolescent and adult rats

    PubMed Central

    Carvalho, A. F.; Reyes, B. A. S.; Ramalhosa, F.; Sousa, N.

    2014-01-01

    Recent studies demonstrate a differential trajectory for cannabinoid receptor expression in cortical and sub-cortical brain areas across postnatal development. In the present study, we sought to investigate whether chronic systemic exposure to a synthetic cannabinoid receptor agonist causes morphological changes in the structure of dendrites and dendritic spines in adolescent and adult pyramidal neurons in the medial prefrontal cortex (mPFC) and medium spiny neurons (MSN) in the nucleus accumbens (Acb). Following systemic administration of WIN 55,212-2 in adolescent (PN 37–40) and adult (P55–60) male rats, the neuronal architecture of pyramidal neurons and MSN was assessed using Golgi–Cox staining. While no structural changes were observed in WIN 55,212-2-treated adolescent subjects compared to control, exposure to WIN 55,212-2 significantly increased dendritic length, spine density and the number of dendritic branches in pyramidal neurons in the mPFC of adult subjects when compared to control and adolescent subjects. In the Acb, WIN 55,212-2 exposure significantly decreased dendritic length and number of branches in adult rat subjects while no changes were observed in the adolescent groups. In contrast, spine density was significantly decreased in both the adult and adolescent groups in the Acb. To determine whether regional developmental morphological changes translated into behavioral differences, WIN 55,212-2-induced aversion was evaluated in both groups using a conditioned place preference paradigm. In adult rats, WIN 55,212-2 administration readily induced conditioned place aversion as previously described. In contrast, adolescent rats did not exhibit aversion following WIN 55,212-2 exposure in the behavioral paradigm. The present results show that synthetic cannabinoid administration differentially impacts cortical and sub-cortical neuronal morphology in adult compared to adolescent subjects. Such differences may underlie the disparate development

  10. Novel cannabinol probes for CB1 and CB2 cannabinoid receptors.

    PubMed

    Mahadevan, A; Siegel, C; Martin, B R; Abood, M E; Beletskaya, I; Razdan, R K

    2000-10-05

    The observation that the phenolic hydroxyl of THCs was important for binding to the CB1 receptor but not as critical for binding to the CB2 receptor prompted us to extend this finding to the cannabinol (CBN) series. To study the SAR of CBN analogues, CBN derivatives with substitution at the C-1, C-3, and C-9 positions were chosen since these positions have played a key role in the SAR of THCs. CBN-3-(1',1'-dimethylheptyl) analogues were prepared by sulfur dehydrogenation of Delta(8)-THC-3-(1',1'-dimethylheptyl) analogues. 9-Substituted CBN analogues were prepared by the standard sulfur dehydrogenation of 9-substituted Delta(8)-THC analogues (Scheme 1), which in turn were prepared following our previous procedure using selenium dioxide oxidation of the corresponding Delta(8)-THCs followed by sodium chlorite oxidation to give the 9-carboxy-Delta(8)-THC derivatives. 11-Hydroxy-CBN analogues were prepared from the corresponding 9-carbomethoxy-CBN analogues by reduction with LiAlH(4). Deoxy-CBN analogue 14 was prepared from the corresponding Delta(8)-THC analogue 11 by conversion of the phenolic hydroxyl to the phosphate derivative 12, followed by lithium ammonia reduction to provide the deoxy-Delta(8)-THC analogue 13, which in turn was dehydrogenated with sulfur to provide the deoxy-CBN analogue 14 (Scheme 2). The various analogues were assayed for binding both to the brain and the peripheral cannabinoid receptors (CB1 and CB2). We have found that the binding profile differs widely between the CBN and the THC series. Specifically, in the CBN series the removal of the phenolic hydroxyl decreases binding affinity to both the CB1 and CB2 receptors, whereas in the THC series, CB1 affinity is selectively reduced. Thus, in the CBN series, the selectivity of binding observed with the removal of the hydroxy group is decreased severalfold as compared to what occurs in the THC series. Generally, high affinity for the CB2 receptor was found in analogues when the phenolic hydroxyl

  11. Peripheral and spinal activation of cannabinoid receptors by joint mobilization alleviates postoperative pain in mice.

    PubMed

    Martins, D F; Mazzardo-Martins, L; Cidral-Filho, F J; Gadotti, V M; Santos, A R S

    2013-01-01

    The present study was undertaken to investigate the relative contribution of cannabinoid receptors (CBRs) subtypes and to analyze cannabimimetic mechanisms involved in the inhibition of anandamide (AEA) and 2-arachidonoyl glycerol degradation on the antihyperalgesic effect of ankle joint mobilization (AJM). Mice (25-35g) were subjected to plantar incision (PI) and 24h after surgery animals received the following treatments, AJM for 9min, AEA (10mg/kg, intraperitoneal [i.p.]), WIN 55,212-2 (1.5mg/kg, i.p.), URB937 (0.01-1mg/kg, i.p.; a fatty acid amide hydrolase [FAAH] inhibitor) or JZL184 (0.016-16mg/kg, i.p.; a monoacylglycerol lipase [MAGL] inhibitor). Withdrawal frequency to mechanical stimuli was assessed 24h after PI and at different time intervals after treatments. Receptor specificity was investigated using selective CB1R (AM281) and CB2R (AM630) antagonists. In addition, the effect of the FAAH and MAGL inhibitors on the antihyperalgesic action of AJM was investigated. AJM, AEA, WIN 55,212-2, URB937 and JZL184 decreased mechanical hyperalgesia induced by PI. The antihyperalgesic effect of AJM was reversed by pretreatment with AM281 given by intraperitoneal and intrathecal routes, but not intraplantarly. Additionally, intraperitoneal and intraplantar, but not intrathecal administration of AM630 blocked AJM-induced antihyperalgesia. Interestingly, in mice pretreated with FAAH or the MAGL inhibitor the antihyperalgesic effect of AJM was significantly longer. This article presents data addressing the CBR mechanisms underlying the antihyperalgesic activity of joint mobilization as well as of the endocannabinoid catabolic enzyme inhibitors in the mouse postoperative pain model. Joint mobilization and these enzymes offer potential targets to treat postoperative pain.

  12. 3-Substituted pyrazole analogs of the cannabinoid type 1 (CB₁) receptor antagonist rimonabant: cannabinoid agonist-like effects in mice via non-CB₁, non-CB₂ mechanism.

    PubMed

    Wiley, Jenny L; Selley, Dana E; Wang, Pinglang; Kottani, Rudresha; Gadthula, Srinivas; Mahadeven, Anu

    2012-02-01

    The prototypic cannabinoid type 1 (CB₁) receptor antagonist/inverse agonist, rimonabant, is comprised of a pyrazole core surrounded by a carboxyamide with terminal piperidine group (3-substituent), a 2,4-dichlorophenyl group (1-substituent), a 4-chlorophenyl group (5-substituent), and a methyl group (4-substituent). Previous structure-activity relationship (SAR) analysis has suggested that the 3-position may be involved in receptor recognition and agonist activity. The goal of the present study was to develop CB₁-selective compounds and explore further the SAR of 3-substitution on the rimonabant template. 3-Substituted analogs with benzyl and alkyl amino, dihydrooxazole, and oxazole moieties were synthesized and evaluated in vitro and in vivo. Several notable patterns emerged. First, most of the analogs exhibited CB₁ selectivity, with many lacking affinity for the CB₂ receptor. Affinity tended to be better when [³H]5-(4-chlorophenyl)-1-(2,4-dichloro-phenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide (SR141716), rather than [³H](-)-cis-3-[2-hydroxy-4(1,1-dimethyl-heptyl)phenyl]-trans-4-(3-hydroxy-propyl)cyclohexanol (CP55,940), was used as the binding radioligand. Second, many of the analogs produced an agonist-like profile of effects in mice (i.e., suppression of activity, antinociception, hypothermia, and immobility); however, their potencies were not well correlated with their CB₁ binding affinities. Further assessment of selected analogs showed that none were effective antagonists of the effects of Δ⁹-tetrahydrocannabinol in mice, their agonist-like effects were not blocked by rimonabant, they were active in vivo in CB₁⁻/⁻ mice, and they failed to stimulate guanosine-5'-O-(3-[³⁵S]thio)-triphosphate binding. Several analogs were inverse agonists in the latter assay. Together, these results suggest that this series of 3-substituted pyrazole analogs represent a novel class of CB₁-selective cannabinoids that produce agonist

  13. Involvement of ERK1/2, cPLA2 and NF-κB in microglia suppression by cannabinoid receptor agonists and antagonists.

    PubMed

    Ribeiro, Rachel; Wen, Jie; Li, Shihe; Zhang, Yumin

    2013-01-01

    Cannabinoids have been consistently shown to suppress microglia activation and the release of cytotoxic factors including nitric oxide, superoxide and proinflammatory cytokines. However, the underlying molecular mechanisms and whether the action of cannabinoids is coupled to the activation of cannabinoid type 1 (CB1) and type 2 (CB2) receptors are still poorly defined. In this study we observed that the CB1 and CB2 receptor non-selective or selective agonists dramatically attenuate iNOS induction and ROS generation in LPS-activated microglia. These effects are due to their reduction of phosphorylation of extracellular signal regulated kinase 1/2 (ERK1/2), cytosolic phospholipase A (cPLA) and activation of NF-κB. Surprisingly, instead of reversing the effect of the respective CB1 and CB2 receptor agonists, the antagonists also suppress iNOS induction and ROS generation in activated microglia by similar mechanisms. Taken together, these results indicate that both cannabinoid receptor agonists and antagonists might suppress microglia activation by CB1 and CB2 receptor independent mechanisms, and provide a new insight into the mechanisms of microglia inhibition by cannabinoids.

  14. Monohydroxylated metabolites of the K2 synthetic cannabinoid JWH-073 retain intermediate to high cannabinoid 1 receptor (CB1R) affinity and exhibit neutral antagonist to partial agonist activity

    PubMed Central

    Brents, Lisa K.; Gallus-Zawada, Anna; Radominska-Pandya, Anna; Vasiljevik, Tamara; Prisinzano, Thomas E.; Fantegrossi, William E.; Moran, Jeffery H.; Prather, Paul L.

    2012-01-01

    K2 and several similar purported “incense products” spiked with synthetic cannabinoids are abused as cannabis substitutes. We hypothesized that metabolism of JWH-073, a prevalent cannabinoid found in K2, contributes to toxicity associated with K2 use. Competition receptor binding studies and G-protein activation assays, both performed by employing mouse brain homogenates, were used to determine the affinity and intrinsic activity, respectively, of potential monohydroxylated (M1, M3–M5) and monocarboxylated (M6) metabolites at cannabinoid 1 receptors (CB1Rs). Surprisingly, M1, M4 and M5 retain nanomolar affinity for CB1Rs, while M3 displays micromolar affinity and M6 does not bind to CB1Rs. JWH-073 displays equivalent efficacy to that of the CB1R full agonist CP-55,940, while M1, M3, and M5 act as CB1R partial agonists, and M4 shows little or no intrinsic activity. Further in vitro investigation by Schild analysis revealed that M4 acts as a competitive neutral CB1R antagonist (Kb~40nM). In agreement with in vitro studies, M4 also demonstrates CB1R antagonism in vivo by blunting cannabinoid-induced hypothermia in mice. Interestingly, M4 does not block agonist-mediated responses of other measures in the cannabinoid tetrad (e.g., locomotor suppression, catalepsy or analgesia). Finally, also as predicted by in vitro results, M1 exhibits agonist activity in vivo by inducing significant hypothermia and suppression of locomotor activity in mice. In conclusion, the present study indicates that further work examining the physiological effects of synthetic cannabinoid metabolism is warranted. Such a complex mix of metabolically produced CB1R ligands may contribute to the adverse effect profile of JWH-073-containing products. PMID:22266354

  15. Monohydroxylated metabolites of the K2 synthetic cannabinoid JWH-073 retain intermediate to high cannabinoid 1 receptor (CB1R) affinity and exhibit neutral antagonist to partial agonist activity.

    PubMed

    Brents, Lisa K; Gallus-Zawada, Anna; Radominska-Pandya, Anna; Vasiljevik, Tamara; Prisinzano, Thomas E; Fantegrossi, William E; Moran, Jeffery H; Prather, Paul L

    2012-04-01

    K2 and several similar purported "incense products" spiked with synthetic cannabinoids are abused as cannabis substitutes. We hypothesized that metabolism of JWH-073, a prevalent cannabinoid found in K2, contributes to toxicity associated with K2 use. Competition receptor binding studies and G-protein activation assays, both performed by employing mouse brain homogenates, were used to determine the affinity and intrinsic activity, respectively, of potential monohydroxylated (M1, M3-M5) and monocarboxylated (M6) metabolites at cannabinoid 1 receptors (CB1Rs). Surprisingly, M1, M4 and M5 retain nanomolar affinity for CB1Rs, while M3 displays micromolar affinity and M6 does not bind to CB1Rs. JWH-073 displays equivalent efficacy to that of the CB1R full agonist CP-55,940, while M1, M3, and M5 act as CB1R partial agonists, and M4 shows little or no intrinsic activity. Further in vitro investigation by Schild analysis revealed that M4 acts as a competitive neutral CB1R antagonist (K(b)∼40nM). In agreement with in vitro studies, M4 also demonstrates CB1R antagonism in vivo by blunting cannabinoid-induced hypothermia in mice. Interestingly, M4 does not block agonist-mediated responses of other measures in the cannabinoid tetrad (e.g., locomotor suppression, catalepsy or analgesia). Finally, also as predicted by in vitro results, M1 exhibits agonist activity in vivo by inducing significant hypothermia and suppression of locomotor activity in mice. In conclusion, the present study indicates that further work examining the physiological effects of synthetic cannabinoid metabolism is warranted. Such a complex mix of metabolically produced CB1R ligands may contribute to the adverse effect profile of JWH-073-containing products.

  16. Cannabinoid type 1 receptors located on single-minded 1-expressing neurons control emotional behaviors.

    PubMed

    Dubreucq, S; Kambire, S; Conforzi, M; Metna-Laurent, M; Cannich, A; Soria-Gomez, E; Richard, E; Marsicano, G; Chaouloff, F

    2012-03-01

    This study has investigated the role of hypothalamic and amygdalar type-1 cannabinoid (CB1) receptors in the emotional and neuroendocrine responses to stress. To do so, we used the Cre/loxP system to generate conditional mutant mice lacking the CB1 gene in neurons expressing the transcription factor single-minded 1 (Sim1). This choice was dictated by former evidence for Sim1-Cre transgenic mice bearing Cre activity in all areas expressing Sim1, which chiefly includes the hypothalamus (especially the paraventricular nucleus, the supraoptic nucleus, and the posterior hypothalamus) and the mediobasal amygdala. Genomic DNA analyses in Sim1-CB1(-/-) mice indicated that the CB1 allele was excised from the hypothalamus and the amygdala, but not from the cortex, the striatum, the thalamus, the nucleus accumbens, the brainstem, the hippocampus, the pituitary gland, and the spinal cord. Double-fluorescent in situ hybridization experiments further indicated that Sim1-CB1(-/-) mice displayed a weaker CB1 receptor mRNA expression in the paraventricular nucleus of the hypothalamus and the mediobasal part of the amygdala, compared to wild-type animals. Individually housed Sim1-CB1(-/-) mice and their Sim1-CB1(+/+) littermates were exposed to anxiety and fear memory tests under basal conditions as well as after acute/repeated social stress. A principal component analysis of the behaviors of Sim1-CB1(-/-) and Sim1-CB1(+/+) mice in anxiety tests (open field, elevated plus-maze, and light/dark box) revealed that CB1 receptors from Sim1-expressing neurons exert tonic, albeit opposite, controls of locomotor and anxiety reactivity to novel environments. No difference between genotypes was observed during the recall of contextual fear conditioning or during active avoidance learning. Sim1-CB1(-/-), but not Sim1-CB1(+/+), mice proved sensitive to an acute social stress as this procedure reverted the increased ambulation in the center of the open field. The stimulatory influence of

  17. The activation of cannabinoid receptors in striatonigral GABAergic neurons inhibited GABA uptake.

    PubMed

    Romero, J; de Miguel, R; Ramos, J A; Fernández-Ruiz, J J

    1998-01-01

    Cannabinoid receptors (CNRs) in basal ganglia are located on striatal efferent neurons which are gamma-aminobutiric acid (GABA)-containing neurons. Recently, we have demonstrated that CN-induced motor inhibition is reversed by GABA-B, but not GABA-A, receptor antagonists, presumably indicating that the activation of CNRs in striatal outflow nuclei, mainly in the substantia nigra, should be followed by an increase of GABA concentrations into the synaptic cleft of GABA-B receptor synapses. The present study was designed to examine whether this was originated by increasing GABA synthesis and/or release or by decreasing GABA uptake. We analyzed: (i) GABA synthesis, by measuring the activity of glutamic acid decarboxylase (GAD) and GABA contents in brain regions that contain striatonigral GABAergic neurons, after in vivo administration of CNs and/or the CNR antagonist SR141716; (ii) [3H]GABA release in vitro in the presence or the absence of a synthetic CN agonist, HU-210, by using perifusion of small fragments of substantia nigra; and (iii) [3H]GABA uptake in vitro in the presence or the absence of WIN-55,212-2, by using synaptosomes obtained from either globus pallidus or substantia nigra. Results were as follows. Delta9-tetrahydrocannabinol (delta9-THC) and HU-210, did not alter neither GAD activity nor GABA contents in both the striatum and the ventral midbrain at any of the two times tested, thus suggesting that CNs apparently failed to change GABA synthesis in striatonigral GABAergic neurons. A similar lack of effect of HU-210 on in vitro [3H]GABA release, both basal and K+-evoked, was seen when this CN was added to perifused substantia nigra fragments, also suggesting no changes at the level of GABA release. However, when synaptosome preparations obtained from the substantia nigra were incubated in the presence of WIN-55,212-2, a decrease in [3H]GABA uptake could be measured. This lowering effect was specific of striatonigral GABAergic neurons since it was not

  18. Changes in the cannabinoid receptor binding, G protein coupling, and cyclic AMP cascade in the CNS of rats tolerant to and dependent on the synthetic cannabinoid compound CP55,940.

    PubMed

    Rubino, T; Viganò, D; Massi, P; Parolaro, D

    2000-11-01

    Chronic exposure to CP55,940 produced a significant down-regulation of cannabinoid receptors in the striatum, cortex, hippocampus, and cerebellum of rat brain. At 24 h after SR141716-precipitated withdrawal, we observed a tendency to return to basal levels in the striatum and cortex, whereas the specific binding remained lower in the hippocampus and cerebellum. When we surveyed cannabinoid receptor-activated G proteins, in chronic CP55,940-treated rats the guanosine 5'-O:-(3-[(35)S]thiotriphosphate) ([(35)S]GTPgammaS) binding assay revealed a decrease of activated G proteins in the striatum, cortex, and hippocampus, whereas no significant changes were seen in the cerebellum. At 24 h after the SR141716-precipitated withdrawal, [(35)S]GTPgammaS binding increased compared with that of rats chronically exposed to CP55,940, attaining the control level except for cerebellum, where we observed a trend to overcome the control amounts. Concerning the cyclic AMP (cAMP) cascade, which represents the major intracellular signaling pathway activated by cannabinoid receptors, in the cerebral areas from rats chronically exposed to CP55,940 we found alteration in neither cAMP levels nor protein kinase A activity. In the brain regions taken from CP55, 940-withdrawn rats, we only observed a significant up-regulation in the cerebellum. Our findings suggest that receptor desensitization and down-regulation are strictly involved in the development of cannabinoid tolerance, whereas alterations in the cAMP cascade in the cerebellum could be relevant in the mediation of the motor component of cannabinoid abstinence.

  19. Cannabinoid CB1 receptors are localized primarily on cholecystokinin-containing GABAergic interneurons in the rat hippocampal formation.

    PubMed

    Tsou, K; Mackie, K; Sañudo-Peña, M C; Walker, J M

    1999-01-01

    Localization of cannabinoid CB 1 receptors on GABAergic interneurons in the rat hippocampal formation was studied by double-labeling immunohistochemistry with confocal microscopy. Virtually all CB1-immunoreactive neurons (95%) are GABAergic. CB 1 fluorescence showed a punctate pattern. In contrast, the GABA fluorescence was distributed homogeneously, suggesting that while CB 1 receptors and GABA exist in the same cells they are not localized in the same subcellular compartments. Although virtually all CB1 neurons were GABAergic, many GABAergic neurons did not contain CB1 receptors. GABAergic interneurons in the hippocampal formation can be further divided into subpopulations with distinct connections and functions, using cell markers such as neuropeptides and calcium binding proteins. CB1 receptors were highly co-localized with cholecystokinin and partially co-localized with calretinin and calbindin, but not with parvalbumin. This suggests that cannabinoids may modulate GABAergic neurotransmission at the synapses on the soma and at synapses on the proximal dendrites of the principal neurons, as well as at synapses on other GABAergic interneurons.

  20. The cannabinoid WIN 55,212-2 inhibits transient receptor potential vanilloid 1 (TRPV1) and evokes peripheral antihyperalgesia via calcineurin.

    PubMed

    Patwardhan, Amol M; Jeske, Nathaniel A; Price, Theodore J; Gamper, Nikita; Akopian, Armen N; Hargreaves, Kenneth M

    2006-07-25

    Cannabinoids can evoke antihyperalgesia and antinociception at a peripheral site of action. However, the signaling pathways mediating these effects are not clearly understood. We tested the hypothesis that certain cannabinoids directly inhibit peripheral capsaicin-sensitive nociceptive neurons by dephosphorylating and desensitizing transient receptor potential vanilloid 1 (TRPV1) via a calcium calcineurin-dependent mechanism. Application of the cannabinoid WIN 55,212-2 (WIN) to cultured trigeminal (TG) neurons or isolated skin biopsies rapidly and significantly inhibited capsaicin-activated inward currents and neuropeptide exocytosis by a mechanism requiring the presence of extracellular calcium. The inhibitory effect did not involve activation of G protein-coupled cannabinoid receptors, because neither pertussis toxin nor GDPbetaS treatments altered the WIN effect. However, application of WIN-activated calcineurin, as measured by nuclear translocation of the nuclear factor of activated T cells (NFAT)c4 transcription factor, dephosphorylated TRPV1. The WIN-induced desensitization of TRPV1 was mediated by calcineurin, because the application of structurally distinct calcineurin antagonists (calcineurin autoinhibitory peptide and cyclosporine/cyclophilin complex) abolished WIN-induced inhibition of capsaicin-evoked inward currents and neuropeptide exocytosis. This mechanism also contributed to peripheral antinociceptive/antihyperalgesic effects of WIN because pretreatment with the calcineurin antagonist calcineurin autoinhibitory peptide (CAIP) significantly reduced peripherally mediated WIN effects in two behavioral models. Collectively, these data demonstrate that cannabinoids such as WIN directly inhibit TRPV1 functional activities via a calcineurin pathway that represents a mechanism of cannabinoid actions at peripheral sites.

  1. Pharmacological blockade of either cannabinoid CB1 or CB2 receptors prevents both cocaine-induced conditioned locomotion and cocaine-induced reduction of cell proliferation in the hippocampus of adult male rat

    PubMed Central

    Blanco-Calvo, Eduardo; Rivera, Patricia; Arrabal, Sergio; Vargas, Antonio; Pavón, Francisco Javier; Serrano, Antonia; Castilla-Ortega, Estela; Galeano, Pablo; Rubio, Leticia; Suárez, Juan; Rodriguez de Fonseca, Fernando

    2014-01-01

    Addiction to major drugs of abuse, such as cocaine, has recently been linked to alterations in adult neurogenesis in the hippocampus. The endogenous cannabinoid system modulates this proliferative response as demonstrated by the finding that pharmacological activation/blockade of cannabinoid CB1 and CB2 receptors not only modulates neurogenesis but also modulates cell death in the brain. In the present study, we evaluated whether the endogenous cannabinoid system affects cocaine-induced alterations in cell proliferation. To this end, we examined whether pharmacological blockade of either CB1 (Rimonabant, 3 mg/kg) or CB2 receptors (AM630, 3 mg/kg) would affect cell proliferation [the cells were labeled with 5-bromo-2′-deoxyuridine (BrdU)] in the subventricular zone (SVZ) of the lateral ventricle and the dentate subgranular zone (SGZ). Additionally, we measured cell apoptosis (as monitored by the expression of cleaved caspase-3) and glial activation [by analyzing the expression of glial fibrillary acidic protein (GFAP) and Iba-1] in the striatum and hippocampus during acute and repeated (4 days) cocaine administration (20 mg/kg). The results showed that acute cocaine exposure decreased the number of BrdU-immunoreactive (ir) cells in the SVZ and SGZ. In contrast, repeated cocaine exposure reduced the number of BrdU-ir cells only in the SVZ. Both acute and repeated cocaine exposure increased the number of cleaved caspase-3-, GFAP- and Iba1-ir cells in the hippocampus, and this effect was counteracted by AM630 or Rimonabant, which increased the number of BrdU-, GFAP-, and Iba1-ir cells in the hippocampus. These results indicate that the changes in neurogenic, apoptotic and gliotic processes that were produced by repeated cocaine administration were normalized by pharmacological blockade of CB1 and CB2. The restorative effects of cannabinoid receptor blockade on hippocampal cell proliferation were associated with the prevention of the induction of conditioned

  2. Coadministration of indomethacin and minocycline attenuates established paclitaxel-induced neuropathic thermal hyperalgesia: Involvement of cannabinoid CB1 receptors

    PubMed Central

    Parvathy, Subramanian S.; Masocha, Willias

    2015-01-01

    Taxanes such as paclitaxel, which are chemotherapeutic drugs, cause dose-dependent painful neuropathy in some patients. We investigated whether coadministration of minocycline and indomethacin produces antinociceptive effects in mice with paclitaxel-induced neuropathic thermal hyperalgesia and if the cannabinoid system is involved. Previously, we reported that coadministration of these two drugs results in antinociception against inflammatory pain at doses where either drug alone lack significant activity. In the current study, we observed that treatment of female mice with indomethacin or minocycline alone did not affect established paclitaxel-induced thermal hyperalgesia, whereas coadministration of the two drugs attenuated it. In male mice indomethacin had some antihyperalgesic activity, whilst minocycline did not. Coadministration of the two drugs had supraadditive antihyperalgesic activity in male mice. Administration of a cannabinoid CB1 receptor antagonist AM 251 blocked the antihyperalgesic effects of the combination of minocycline and indomethacin in both male and female mice. In conclusion our results indicate that coadministration of minocycline and indomethacin abrogates established paclitaxel-induced neuropathic thermal hyperalgesia in mice, and the potentiation of the antinociceptive effects of this combination involves the cannabinoid system. PMID:26085115

  3. FAAH-/- mice display differential tolerance, dependence, and cannabinoid receptor adaptation after delta 9-tetrahydrocannabinol and anandamide administration.

    PubMed

    Falenski, Katherine W; Thorpe, Andrew J; Schlosburg, Joel E; Cravatt, Benjamin F; Abdullah, Rehab A; Smith, Tricia H; Selley, Dana E; Lichtman, Aron H; Sim-Selley, Laura J

    2010-07-01

    Repeated administration of Delta(9)-tetrahydrocannabinol (THC), the primary psychoactive constituent of Cannabis sativa, induces profound tolerance that correlates with desensitization and downregulation of CB(1) cannabinoid receptors in the CNS. However, the consequences of repeated administration of the endocannabinoid N-arachidonoyl ethanolamine (anandamide, AEA) on cannabinoid receptor regulation are unclear because of its rapid metabolism by fatty acid amide hydrolase (FAAH). FAAH(-/-) mice dosed subchronically with equi-active maximally effective doses of AEA or THC displayed greater rightward shifts in THC dose-effect curves for antinociception, catalepsy, and hypothermia than in AEA dose-effect curves. Subchronic THC significantly attenuated agonist-stimulated [(35)S]GTP gamma S binding in brain and spinal cord, and reduced [(3)H]WIN55,212-2 binding in brain. Interestingly, AEA-treated FAAH(-/-) mice showed less CB(1) receptor downregulation and desensitization than THC-treated mice. Experiments examining tolerance and cross-tolerance indicated that the behavioral effects of THC, a low efficacy CB(1) receptor agonist, were more sensitive to receptor loss than those of AEA, a higher efficacy agonist, suggesting that the expression of tolerance was more affected by the intrinsic activity of the ligand at testing than during subchronic treatment. In addition, the CB(1) receptor antagonist, rimonabant, precipitated a markedly reduced magnitude of withdrawal in FAAH(-/-) mice treated subchronically with AEA compared with mice treated repeatedly with THC. The findings that repeated AEA administration produces lesser adaptive changes at the CB(1) receptor and has reduced dependence liability compared with THC suggest that pharmacotherapies targeting endocannabinoid catabolic enzymes are less likely to promote tolerance and dependence than direct acting CB(1) receptor agonists.

  4. A2A Adenosine Receptor Antagonism Enhances Synaptic and Motor Effects of Cocaine via CB1 Cannabinoid Receptor Activation

    PubMed Central

    Tozzi, Alessandro; de Iure, Antonio; Marsili, Valentina; Romano, Rosaria; Tantucci, Michela; Di Filippo, Massimiliano; Costa, Cinzia; Napolitano, Francesco; Mercuri, Nicola Biagio; Borsini, Franco; Giampà, Carmen; Fusco, Francesca Romana; Picconi, Barbara; Usiello, Alessandro; Calabresi, Paolo

    2012-01-01

    Background Cocaine increases the level of endogenous dopamine (DA) in the striatum by blocking the DA transporter. Endogenous DA modulates glutamatergic inputs to striatal neurons and this modulation influences motor activity. Since D2 DA and A2A-adenosine receptors (A2A-Rs) have antagonistic effects on striatal neurons, drugs targeting adenosine receptors such as caffeine-like compounds, could enhance psychomotor stimulant effects of cocaine. In this study, we analyzed the electrophysiological effects of cocaine and A2A-Rs antagonists in striatal slices and the motor effects produced by this pharmacological modulation in rodents. Principal Findings Concomitant administration of cocaine and A2A-Rs antagonists reduced glutamatergic synaptic transmission in striatal spiny neurons while these drugs failed to produce this effect when given in isolation. This inhibitory effect was dependent on the activation of D2-like receptors and the release of endocannabinoids since it was prevented by L-sulpiride and reduced by a CB1 receptor antagonist. Combined application of cocaine and A2A-R antagonists also reduced the firing frequency of striatal cholinergic interneurons suggesting that changes in cholinergic tone might contribute to this synaptic modulation. Finally, A2A-Rs antagonists, in the presence of a sub-threshold dose of cocaine, enhanced locomotion and, in line with the electrophysiological experiments, this enhanced activity required activation of D2-like and CB1 receptors. Conclusions The present study provides a possible synaptic mechanism explaining how caffeine-like compounds could enhance psychomotor stimulant effects of cocaine. PMID:22715379

  5. Non-Selective Cannabinoid Receptor Antagonists, Hinokiresinols Reduce Infiltration of Microglia/Macrophages into Ischemic Brain Lesions in Rat via Modulating 2-Arachidonolyglycerol-Induced Migration and Mitochondrial Activity

    PubMed Central

    Anthony Jalin, Angela M. A.; Rajasekaran, Maheswari; Prather, Paul L.; Kwon, Jin Sun; Gajulapati, Veeraswamy; Choi, Yongseok; Kim, Chunsook; Pahk, Kisoo; Ju, Chung; Kim, Won-Ki

    2015-01-01

    Growing evidence suggests that therapeutic strategies to modulate the post-ischemic inflammatory responses are promising approaches to improve stroke outcome. Although the endocannabinoid system has been emerged as an endogenous therapeutic target to regulate inflammation after stroke insult, the downstream mechanisms and their potentials for therapeutic intervention remain controversial. Here we identified trans- and cis-hinokiresinols as novel non-selective antagonists for two G-protein-coupled cannabinoid receptors, cannabinoid receptor type 1 and type 2. The Electric Cell-substrate Impedance Sensing and Boyden chamber migration assays using primary microglial cultures revealed that both hinokiresinols significantly inhibited an endocannabinoid, 2-arachidonoylglycerol-induced migration. Hinokiresinols modulated 2-arachidonoylglycerol-induced mitochondrial bioenergetics in microglia as evidenced by inhibition of ATP turnover and reduction in respiratory capacity, thereby resulting in impaired migration activity. In rats subjected to transient middle cerebral artery occlusion (1.5-h) followed by 24-h reperfusion, post-ischemic treatment with hinokiresinols (2 and 7-h after the onset of ischemia, 10 mg/kg) significantly reduced cerebral infarct and infiltration of ED1-positive microglial/macrophage cells into cerebral ischemic lesions in vivo. Co-administration of exogenous 2-AG (1 mg/kg, i.v., single dose at 2 h after starting MCAO) abolished the protective effect of trans-hinokiresionol. These results suggest that hinokiresinols may serve as stroke treatment by targeting the endocannabinoid system. Alteration of mitochondrial bioenergetics and consequent inhibition of inflammatory cells migration may be a novel mechanism underlying anti-ischemic effects conferred by cannabinoid receptor antagonists. PMID:26517721

  6. Enhancement of endocannabinoid neurotransmission through CB1 cannabinoid receptors counteracts the reinforcing and psychostimulant effects of cocaine.

    PubMed

    Vlachou, Styliani; Stamatopoulou, Fygaleia; Nomikos, George G; Panagis, George

    2008-11-01

    Cannabinoids, in contrast to typical drugs of abuse, have been shown to exert complex effects on behavioural reinforcement and psychomotor function. We have shown that cannabinoid agonists lack reinforcing/rewarding properties in the intracranial self-stimulation (ICSS) paradigm and that the CB1 receptor (CB1R) agonist WIN55,212-2 attenuates the reward-facilitating actions of cocaine. We sought to determine the effects of the endocannabinoid neurotransmission enhancer AM-404 (1, 3, 10, 30 mg/kg) on the changes in ICSS threshold and locomotion elicited by cocaine and extend the study of the effects of WIN55,212-2 (0.3, 1, 3 mg/kg) on cocaine-induced hyperlocomotion. AM-404 did not exhibit reward-facilitating properties, and actually increased self-stimulation threshold at the highest dose. Cocaine significantly reduced self-stimulation threshold, without altering maximal rates of responding. AM-404 (10 mg/kg) attenuated this action of cocaine, an effect which was reversed by pretreatment with the selective CB1R antagonist SR141716A. WIN55,212-2 decreased locomotion at the two highest doses, an effect that was blocked by SR141716A; AM-404 had no effect on locomotion. Cocaine caused a significant, dose-dependent increase in locomotion, which was reduced by WIN55,212-2 and AM-404. SR141716A blocked the effects of WIN55,212-2 and AM-404 on cocaine-induced hyperlocomotion. SR141716A alone had no effect on ICSS threshold or locomotion. These results indicate that cannabinoids may interfere with brain reward systems responsible for the expression of acute reinforcing/rewarding properties of cocaine, and provide further evidence that the cannabinoid system could be explored as a potential drug discovery target for the treatment of psychostimulant addiction and pathological states associated with psychomotor overexcitability.

  7. The effects of cannabinoid CB1, CB2 and vanilloid TRPV1 receptor antagonists on cocaine addictive behavior in rats.

    PubMed

    Adamczyk, Przemysław; Miszkiel, Joanna; McCreary, Andrew C; Filip, Małgorzata; Papp, Mariusz; Przegaliński, Edmund

    2012-03-20

    There is evidence that indicates that tonic activation of cannabinoid CB1 receptors plays a role in extinction/reinstatement of cocaine seeking-behavior but is not involved in the maintenance of cocaine self-administration. To further explore the importance of other endocannabinoid-related receptors in an animal model of cocaine addiction, the present paper examines cannabinoid CB2 receptor antagonist N-((1S)-endo-1,3,3-trimethylbicyclo(2.2.1)heptan-2-yl)-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528) and the transient receptor potential vanilloid type-1 (TRPV1) receptor antagonist N-(3-methoxyphenyl)-4-chlorocinnamide (SB366791) on intravenous (i.v.) cocaine self-administration and extinction/reinstatement of cocaine-seeking behavior in rats. For comparison and reference purposes, the effect of the cannabinoid CB1 receptor antagonist N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251) was also examined. Moreover, for comparison effects of those drugs on operant lever responding for artificial (cocaine) vs. natural (food) reward, food self-administration was also evaluated. Our findings show that AM251 (1-3mg/kg), SR144528 (0.1-1mg/kg) and SB366791 (0.3-1mg/kg) did not affect cocaine self-administration. However, AM251 (0.1-1mg/kg), SR144528 (0.1-1mg/kg) and SB366791 (0.1-1mg/kg) decreased cocaine-induced reinstatement of cocaine-seeking behavior, and AM251 (0.3-1mg/kg) decreased cue-induced reinstatement. Moreover, AM251 (3mg/kg), SR144528 (0.1-1mg/kg) and SB366791 (0.1-1mg/kg) slightly decreased food self-administration behavior, but only AM251 (3mg/kg) reduced food reward. In conclusion, our results indicate for the first time, that tonic activation of CB2 or TRPV1 receptors is involved in cocaine-induced reinstatement of cocaine-seeking behavior, but their activity is not necessary for the rewarding effect of this psychostimulant. In contrast to CB1 receptors, neither CB2 nor

  8. Cannabinoid Receptors Modulate Neuronal Morphology and AnkyrinG Density at the Axon Initial Segment

    PubMed Central

    Tapia, Mónica; Dominguez, Ana; Zhang, Wei; del Puerto, Ana; Ciorraga, María; Benitez, María José; Guaza, Carmen; Garrido, Juan José

    2017-01-01

    Neuronal polarization underlies the ability of neurons to integrate and transmit information. This process begins early in development with axon outgrowth, followed by dendritic growth and subsequent maturation. In between these two steps, the axon initial segment (AIS), a subcellular domain crucial for generating action potentials (APs) and maintaining the morphological and functional polarization, starts to develop. However, the cellular/molecular mechanisms and receptors involved in AIS initial development and maturation are mostly unknown. In this study, we have focused on the role of the type-1 cannabinoid receptor (CB1R), a highly abundant G-protein coupled receptor (GPCR) in the nervous system largely involved in different phases of neuronal development and differentiation. Although CB1R activity modulation has been related to changes in axons or dendrites, its possible role as a modulator of AIS development has not been yet explored. Here we analyzed the potential role of CB1R on neuronal morphology and AIS development using pharmacological and RNA interference approaches in cultured hippocampal neurons. CB1R inhibition, at a very early developmental stage, has no effect on axonal growth, yet CB1R activation can promote it. By contrast, subsequent dendritic growth is impaired by CB1R inhibition, which also reduces ankyrinG density at the AIS. Moreover, our data show a significant correlation between early dendritic growth and ankyrinG density. However, CB1R inhibition in later developmental stages after dendrites are formed only reduces ankyrinG accumulation at the AIS. In conclusion, our data suggest that neuronal CB1R basal activity plays a role in initial development of dendrites and indirectly in AIS proteins accumulation. Based on the lack of CB1R expression at the AIS, we hypothesize that CB1R mediated modulation of dendritic arbor size during early development indirectly determines the accumulation of ankyrinG and AIS development. Further studies

  9. Cannabinoid Receptors Modulate Neuronal Morphology and AnkyrinG Density at the Axon Initial Segment.

    PubMed

    Tapia, Mónica; Dominguez, Ana; Zhang, Wei; Del Puerto, Ana; Ciorraga, María; Benitez, María José; Guaza, Carmen; Garrido, Juan José

    2017-01-01

    Neuronal polarization underlies the ability of neurons to integrate and transmit information. This process begins early in development with axon outgrowth, followed by dendritic growth and subsequent maturation. In between these two steps, the axon initial segment (AIS), a subcellular domain crucial for generating action potentials (APs) and maintaining the morphological and functional polarization, starts to develop. However, the cellular/molecular mechanisms and receptors involved in AIS initial development and maturation are mostly unknown. In this study, we have focused on the role of the type-1 cannabinoid receptor (CB1R), a highly abundant G-protein coupled receptor (GPCR) in the nervous system largely involved in different phases of neuronal development and differentiation. Although CB1R activity modulation has been related to changes in axons or dendrites, its possible role as a modulator of AIS development has not been yet explored. Here we analyzed the potential role of CB1R on neuronal morphology and AIS development using pharmacological and RNA interference approaches in cultured hippocampal neurons. CB1R inhibition, at a very early developmental stage, has no effect on axonal growth, yet CB1R activation can promote it. By contrast, subsequent dendritic growth is impaired by CB1R inhibition, which also reduces ankyrinG density at the AIS. Moreover, our data show a significant correlation between early dendritic growth and ankyrinG density. However, CB1R inhibition in later developmental stages after dendrites are formed only reduces ankyrinG accumulation at the AIS. In conclusion, our data suggest that neuronal CB1R basal activity plays a role in initial development of dendrites and indirectly in AIS proteins accumulation. Based on the lack of CB1R expression at the AIS, we hypothesize that CB1R mediated modulation of dendritic arbor size during early development indirectly determines the accumulation of ankyrinG and AIS development. Further studies

  10. Cannabinoid CB1 Receptors Are Localized in Striated Muscle Mitochondria and Regulate Mitochondrial Respiration

    PubMed Central

    Mendizabal-Zubiaga, Juan; Melser, Su; Bénard, Giovanni; Ramos, Almudena; Reguero, Leire; Arrabal, Sergio; Elezgarai, Izaskun; Gerrikagoitia, Inmaculada; Suarez, Juan; Rodríguez De Fonseca, Fernando; Puente, Nagore; Marsicano, Giovanni; Grandes, Pedro

    2016-01-01

    The cannabinoid type 1 (CB1) receptor is widely distributed in the brain and peripheral organs where it regulates cellular functions and metabolism. In the brain, CB1 is mainly localized on presynaptic axon terminals but is also found on mitochondria (mtCB1), where it regulates cellular respiration and energy production. Likewise, CB1 is localized on muscle mitochondria, but very little is known about it. The aim of this study was to further investigate in detail the distribution and functional role of mtCB1 in three different striated muscles. Immunoelectron microscopy for CB1 was used in skeletal muscles (gastrocnemius and rectus abdominis) and myocardium from wild-type and CB1-KO mice. Functional assessments were performed in mitochondria purified from the heart of the mice and the mitochondrial oxygen consumption upon application of different acute delta-9-tetrahydrocannabinol (Δ9-THC) concentrations (100 nM or 200 nM) was monitored. About 26% of the mitochondrial profiles in gastrocnemius, 22% in the rectus abdominis and 17% in the myocardium expressed CB1. Furthermore, the proportion of mtCB1 versus total CB1 immunoparticles was about 60% in the gastrocnemius, 55% in the rectus abdominis and 78% in the myocardium. Importantly, the CB1 immunolabeling pattern disappeared in muscles of CB1-KO mice. Functionally, acute 100 nM or 200 nM THC treatment specifically decreased mitochondria coupled respiration between 12 and 15% in wild-type isolated mitochondria of myocardial muscles but no significant difference was noticed between THC treated and vehicle in mitochondria isolated from CB1-KO heart. Furthermore, gene expression of key enzymes involved in pyruvate synthesis, tricarboxylic acid (TCA) cycle and mitochondrial respiratory chain was evaluated in the striated muscle of CB1-WT and CB1-KO. CB1-KO showed an increase in the gene expression of Eno3, Pkm2, and Pdha1, suggesting an increased production of pyruvate. In contrast, no significant difference was

  11. Behavioral effects of D3 receptor inhibition and 5-HT4 receptor activation on animals undergoing chronic cannabinoid exposure during adolescence.

    PubMed

    Abboussi, Oualid; Said, Nadia; Fifel, Karim; Lakehayli, Sara; Tazi, Abdelouahhab; El Ganouni, Soumaya

    2016-04-01

    Chronic exposure to cannabinoids during adolescence results in long-lasting behavioral deficits that match some symptomatologic aspects of schizophrenia. The aim of this study was to investigate the reversibility of the emotional and the cognitive effects of chronic exposure to cannabinoids during adolescence, via subsequent modulation of the serotoninergic 5-HT4 and dopaminergic D3 receptors. RS67333 as a 5-HT4 agonist and U-99194A as a D3 antagonist were administered separately at 1 mg/kg and 20 mg/kg, and in combination at 0.5 mg/kg and 10 mg/kg to adult animals undergoing chronic treatment with the synthetic cannabinoid receptor agonist WIN55,212-2 (1 mg/kg) during adolescence. Animals were tested for anxiety-like behavior and episodic-like memory in the open field and novel object recognition tests respectively 30 minutes after the last drug administration. Chronic WIN55,212-2 treated animals exhibited a lasting disruption of episodic memory and increased anxiety levels. The effect on episodic-like memory were partially restored by acute administration of RS67333 and U-99194A and completely by administration of both drugs in combination at lower doses. However, only RS67333 (20 mg/kg) improved the anxiogenic-like effect of WIN55,212-2. These findings give further support that chronic exposure to cannabinoids during adolescence may be used as an animal model for schizophrenia, and highlight D3 and 5-HT4 receptors as potential targets for an enhanced treatment of the cognitive aspect of this disease.

  12. Cannabinoid receptor-mediated antinociception with acetaminophen drug combinations in rats with neuropathic spinal cord injury pain

    PubMed Central

    Hama, Aldric T.; Sagen, Jacqueline

    2010-01-01

    Pre-clinical evidence demonstrates that neuropathic spinal cord injury (SCI) pain is maintained by a number of neurobiological mechanisms, suggesting that treatments directed at several pain-related targets may be more advantageous compared to a treatment focused on a single target. The current study evaluated the efficacy of the non-opiate analgesic acetaminophen, which has several putative analgesic mechanisms, combined with analgesic drugs used to treat neuropathic pain in a rat model of below-level neuropathic SCI pain. Following an acute compression of the mid-thoracic spinal cord, rats exhibited robust hind paw hypersensitivity to innocuous mechanical stimulation. Fifty percent antinociceptive doses of gabapentin, morphine, tramadol or memantine were combined with an ineffective dose of acetaminophen; acetaminophen alone was not antinociceptive. The combination of acetaminophen with either tramadol or memantine resulted in an additive antinociceptive effect. Acetaminophen combined with either morphine or gabapentin, however, resulted in supra-additive (synergistic) efficacy. One of the analgesic mechanisms of acetaminophen is inhibiting the uptake of endocannabinoids from the extracellular space. Pre-treatment with AM251, a cannabinoid receptor subtype-1 (CB1) antagonist, significantly diminished the antinociceptive effect of the acetaminophen+gabapentin combination. Pre-treatment with AM630, a cannabinoid receptor subtype-2 (CB2) antagonist, did not have an effect on this combination. By contrast, both AM251 and AM630 reduced the efficacy of the acetaminophen+morphine combination. None of the active drugs alone were affected by either CB receptor antagonist. The results imply that modulation of the endocannabinoid system in addition to other mechanisms mediate the synergistic antinociceptive effects of acetaminophen combinations. Despite the presence of a cannabinoid mechanism, synergism was not present in all acetaminophen combinations. The combination of

  13. Cannabinoid receptor antagonist-induced striated muscle toxicity and ethylmalonic-adipic aciduria in beagle dogs.

    PubMed

    Tomlinson, Lindsay; Tirmenstein, Mark A; Janovitz, Evan B; Aranibar, Nelly; Ott, Karl-Heinz; Kozlosky, John C; Patrone, Laura M; Achanzar, William E; Augustine, Karen A; Brannen, Kimberly C; Carlson, Kenneth E; Charlap, Jeffrey H; Dubrow, Katherine M; Kang, Liya; Rosini, Laura T; Panzica-Kelly, Julieta M; Flint, Oliver P; Moulin, Frederic J; Megill, John R; Zhang, Haiying; Bennett, Michael J; Horvath, Joseph J

    2012-10-01

    Ibipinabant (IBI), a potent cannabinoid-1 receptor (CB1R) antagonist, previously in development for the treatment of obesity, causes skeletal and cardiac myopathy in beagle dogs. This toxicity was characterized by increases in muscle-derived enzyme activity in serum and microscopic striated muscle degeneration and accumulation of lipid droplets in myofibers. Additional changes in serum chemistry included decreases in glucose and increases in non-esterified fatty acids and cholesterol, and metabolic acidosis, consistent with disturbances in lipid and carbohydrate metabolism. No evidence of CB1R expression was detected in dog striated muscle as assessed by polymerase chain reaction, immunohistochemistry, Western blot analysis, and competitive radioligand binding. Investigative studies utilized metabonomic technology and demonstrated changes in several intermediates and metabolites of fatty acid metabolism including plasma acylcarnitines and urinary ethylmalonate, methylsuccinate, adipate, suberate, hexanoylglycine, sarcosine, dimethylglycine, isovalerylglycine, and 2-hydroxyglutarate. These results indicated that the toxic effect of IBI on striated muscle in beagle dogs is consistent with an inhibition of the mitochondrial flavin-containing enzymes including dimethyl glycine, sarcosine, isovaleryl-CoA, 2-hydroxyglutarate, and multiple acyl-CoA (short, medium, long, and very long chain) dehydrogenases. All of these enzymes converge at the level of electron transfer flavoprotein (ETF) and ETF oxidoreductase. Urinary ethylmalonate was shown to be a biomarker of IBI-induced striated muscle toxicity in dogs and could provide the ability to monitor potential IBI-induced toxic myopathy in humans. We propose that IBI-induced toxic myopathy in beagle dogs is not caused by direct antagonism of CB1R and could represent a model of ethylmalonic-adipic aciduria in humans.

  14. Hybrid inhibitor of peripheral cannabinoid-1 receptors and inducible nitric oxide synthase mitigates liver fibrosis

    PubMed Central

    Iyer, Malliga R.; Liu, Ziyi; Cao, Zongxian; Jourdan, Tony; Erdelyi, Katalin; Godlewski, Grzegorz; Szanda, Gergő; Liu, Jie; Park, Joshua K.; Mukhopadhyay, Bani; Rosenberg, Avi Z.; Liow, Jeih-San; Lorenz, Robin G.; Pacher, Pal; Innis, Robert B.

    2016-01-01

    Liver fibrosis, a consequence of chronic liver injury and a way station to cirrhosis and hepatocellular carcinoma, lacks effective treatment. Endocannabinoids acting via cannabinoid-1 receptors (CB1R) induce profibrotic gene expression and promote pathologies that predispose to liver fibrosis. CB1R antagonists produce opposite effects, but their therapeutic development was halted due to neuropsychiatric side effects. Inducible nitric oxide synthase (iNOS) also promotes liver fibrosis and its underlying pathologies, but iNOS inhibitors tested to date showed limited therapeutic efficacy in inflammatory diseases. Here, we introduce a peripherally restricted, orally bioavailable CB1R antagonist, which accumulates in liver to release an iNOS inhibitory leaving group. In mouse models of fibrosis induced by CCl4 or bile duct ligation, the hybrid CB1R/iNOS antagonist surpassed the antifibrotic efficacy of the CB1R antagonist rimonabant or the iNOS inhibitor 1400W, without inducing anxiety-like behaviors or CB1R occupancy in the CNS. The hybrid inhibitor also targeted CB1R-independent, iNOS-mediated profibrotic pathways, including increased PDGF, Nlrp3/Asc3, and integrin αvβ6 signaling, as judged by its ability to inhibit these pathways in cnr1–/– but not in nos2–/– mice. Additionally, it was able to slow fibrosis progression and to attenuate established fibrosis. Thus, dual-target peripheral CB1R/iNOS antagonists have therapeutic potential in liver fibrosis. PMID:27525312

  15. Presynaptic CB(1) cannabinoid receptors control frontocortical serotonin and glutamate release--species differences.

    PubMed

    Ferreira, Samira G; Teixeira, Filipe M; Garção, Pedro; Agostinho, Paula; Ledent, Catherine; Cortes, Luísa; Mackie, Ken; Köfalvi, Attila

    2012-07-01

    Both the serotonergic and endocannabinoid systems modulate frontocortical glutamate release; thus they are well positioned to participate in the pathogenesis of psychiatric disorders. With the help of fluorescent and confocal microscopy, we localized the CB(1) cannabinoid receptor (CB(1)R) in VGLUT1- and 2- (i.e. glutamatergic) and serotonin transporter- (i.e. serotonergic) -positive fibers and nerve terminals in the mouse and rat frontal cortex. CB(1)R activation by the synthetic agonists, WIN55212-2 (1 μM) and R-methanandamide (1 μM) inhibited the simultaneously measured evoked Ca(2+)-dependent release of [(14)C]glutamate and [(3)H]serotonin from frontocortical nerve terminals of Wistar rats, in a fashion sensitive to the CB(1)R antagonists, O-2050 (1 μM) and LY320135 (5 μM). CB(1)R agonists also inhibited the evoked release of [(14)C]glutamate in C57BL/6J mice in a reversible fashion upon washout. Interestingly, the evoked release of [(14)C]glutamate and [(3)H]serotonin was significantly greater in the CB(1)R knockout CD-1 mice. Furthermore, CB(1)R binding experiments revealed similar frontocortical CB(1)R density in the rat and the CD-1 mouse. Still, the evoked release of [(3)H]serotonin was modulated by neither CB(1)R agonists nor antagonists in wild-type CD-1 or C57BL/6J mice. Altogether, this is the first study to demonstrate functional presynaptic CB(1)Rs in frontocortical glutamatergic and serotonergic terminals, revealing species differences.

  16. Activation of cannabinoid CB1 and CB2 receptors suppresses neuropathic nociception evoked by the chemotherapeutic agent vincristine in rats

    PubMed Central

    Rahn, E J; Makriyannis, A; Hohmann, A G

    2007-01-01

    Background and purpose: The ability of cannabinoids to suppress mechanical hypersensitivity (mechanical allodynia) induced by treatment with the chemotherapeutic agent vincristine was evaluated in rats. Sites of action were subsequently identified. Experimental approach: Mechanical hypersensitivity developed over the course of ten daily injections of vincristine relative to groups receiving saline at the same times. Effects of the CB1/CB2 receptor agonist WIN55,212-2, the receptor-inactive enantiomer WIN55,212-3, the CB2-selective agonist (R,S)-AM1241, the opiate agonist morphine and vehicle on chemotherapy-induced neuropathy were evaluated. WIN55,212-2 was administered intrathecally (i.t.) or locally in the hindpaw to identify sites of action. Pharmacological specificity was established using competitive antagonists for CB1 (SR141716) or CB2 receptors (SR144528). Key results: Systemic administration of WIN55,212-2, but not WIN55,212-3, suppressed vincristine-evoked mechanical allodynia. A leftward shift in the dose-response curve was observed following WIN55,212-2 relative to morphine treatment. The CB1 (SR141716) and CB2 (SR144528) antagonists blocked the anti-allodynic effects of WIN55,212-2. (R,S)-AM1241 suppressed vincristine-induced mechanical hypersensitivity through a CB2 mechanism. Both cannabinoid agonists suppressed vincristine-induced mechanical hypersensitivity without inducing catalepsy. Spinal sites of action are implicated in cannabinoid modulation of chemotherapy-induced neuropathy. WIN55,212-2, but not WIN55,212-3, administered i.t. suppressed vincristine-evoked mechanical hypersensitivity at doses that were inactive following local hindpaw administration. Spinal coadministration of both the CB1 and CB2 antagonists blocked the anti-allodynic effects of WIN55,212-2. Conclusions and implications: Cannabinoids suppress the maintenance of vincristine-induced mechanical allodynia through activation of CB1 and CB2 receptors. These anti-allodynic effects

  17. Orphan nuclear receptor oestrogen-related receptor γ (ERRγ) plays a key role in hepatic cannabinoid receptor type 1-mediated induction of CYP7A1 gene expression

    PubMed Central

    Zhang, Yaochen; Kim, Don-Kyu; Lee, Ji-Min; Park, Seung Bum; Jeong, Won-IL; Kim, Seong Heon; Lee, In-Kyu; Lee, Chul-Ho; Chiang, John Y.L.; Choi, Hueng-Sik

    2017-01-01

    Bile acids are primarily synthesized from cholesterol in the liver and have important roles in dietary lipid absorption and cholesterol homoeostasis. Detailed roles of the orphan nuclear receptors regulating cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid synthesis, have not yet been fully elucidated. In the present study, we report that oestrogen-related receptor γ (ERRγ) is a novel transcriptional regulator of CYP7A1 expression. Activation of cannabinoid receptor type 1 (CB1 receptor) signalling induced ERRγ-mediated transcription of the CYP7A1 gene. Overexpression of ERRγ increased CYP7A1 expression in vitro and in vivo, whereas knockdown of ERRγ attenuated CYP7A1 expression. Deletion analysis of the CYP7A1 gene promoter and a ChIP assay revealed an ERRγ -binding site on the CYP7A1 gene promoter. Small heterodimer partner (SHP) inhibited the transcriptional activity of ERRγ and thus regulated CYP7A1 expression. Overexpression of ERRγ led to increased bile acid levels, whereas an inverse agonist of ERRγ, GSK5182, reduced CYP7A1 expression and bile acid synthesis. Finally, GSK5182 significantly reduced hepatic CB1 receptor-mediated induction of CYP7A1 expression and bile acid synthesis in alcohol-treated mice. These results provide the molecular mechanism linking ERRγ and bile acid metabolism. PMID:26348907

  18. Orphan nuclear receptor oestrogen-related receptor γ (ERRγ) plays a key role in hepatic cannabinoid receptor type 1-mediated induction of CYP7A1 gene expression.

    PubMed

    Zhang, Yaochen; Kim, Don-Kyu; Lee, Ji-Min; Park, Seung Bum; Jeong, Won-Il; Kim, Seong Heon; Lee, In-Kyu; Lee, Chul-Ho; Chiang, John Y L; Choi, Hueng-Sik

    2015-09-01

    Bile acids are primarily synthesized from cholesterol in the liver and have important roles in dietary lipid absorption and cholesterol homoeostasis. Detailed roles of the orphan nuclear receptors regulating cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid synthesis, have not yet been fully elucidated. In the present study, we report that oestrogen-related receptor γ (ERRγ) is a novel transcriptional regulator of CYP7A1 expression. Activation of cannabinoid receptor type 1 (CB1 receptor) signalling induced ERRγ-mediated transcription of the CYP7A1 gene. Overexpression of ERRγ increased CYP7A1 expression in vitro and in vivo, whereas knockdown of ERRγ attenuated CYP7A1 expression. Deletion analysis of the CYP7A1 gene promoter and a ChIP assay revealed an ERRγ-binding site on the CYP7A1 gene promoter. Small heterodimer partner (SHP) inhibited the transcriptional activity of ERRγ and thus regulated CYP7A1 expression. Overexpression of ERRγ led to increased bile acid levels, whereas an inverse agonist of ERRγ, GSK5182, reduced CYP7A1 expression and bile acid synthesis. Finally, GSK5182 significantly reduced hepatic CB1 receptor-mediated induction of CYP7A1 expression and bile acid synthesis in alcohol-treated mice. These results provide the molecular mechanism linking ERRγ and bile acid metabolism.

  19. Association of polymorphisms of the cannabinoid receptor (CNR1) and fatty acid amide hydrolase (FAAH) genes with heroin addiction: impact of long repeats of CNR1.

    PubMed

    Proudnikov, D; Kroslak, T; Sipe, J C; Randesi, M; Li, D; Hamon, S; Ho, A; Ott, J; Kreek, M J

    2010-06-01

    Alterations in expression of a cannabinoid receptor (CNR1, CB1), and of fatty acid amide hydrolase (FAAH) that degrades endogenous ligands of CB1, may contribute to the development of addiction. The 385C>A in the FAAH gene and six polymorphisms of CNR1 were genotyped in former heroin addicts and control subjects (247 Caucasians, 161 Hispanics, 179 African Americans and 19 Asians). In Caucasians, long repeats (>or=14) of 18087-18131(TAA)(8-17) were associated with heroin addiction (P=0.0102). Across three ethnicities combined, a highly significant association of long repeats with heroin addiction was found (z=3.322, P=0.0009). Point-wise significant associations of allele 1359A (P=0.006) and genotype 1359AA (P=0.034) with protection from heroin addiction were found in Caucasians. Also in Caucasians, the genotype pattern, 1359G>A and -6274A>T, was significantly associated with heroin addiction experiment wise (P=0.0244). No association of FAAH 385C>A with heroin addiction was found in any group studied.

  20. Cannabinoid CB2 receptor (CB2R) stimulation delays rubrospinal mitochondrial-dependent degeneration and improves functional recovery after spinal cord hemisection by ERK1/2 inactivation.

    PubMed

    Latini, L; Bisicchia, E; Sasso, V; Chiurchiù, V; Cavallucci, V; Molinari, M; Maccarrone, M; Viscomi, M T

    2014-09-04

    Spinal cord injury (SCI) is a devastating condition of CNS that often results in severe functional impairments for which there are no restorative therapies. As in other CNS injuries, in addition to the effects that are related to the primary site of damage, these impairments are caused by degeneration of distal regions that are connected functionally to the primary lesion site. Modulation of the endocannabinoid system (ECS) counteracts this neurodegeneration, and pharmacological modulation of type-2 cannabinoid receptor (CB2R) is a promising therapeutic target for several CNS pathologies, including SCI. This study examined the effects of CB2R modulation on the fate of axotomized rubrospinal neurons (RSNs) and functional recovery in a model of spinal cord dorsal hemisection (SCH) at the cervical level in rats. SCH induced CB2R expression, severe atrophy, and cell death in contralateral RSNs. Furthermore, SCH affected molecular changes in the apoptotic cascade in RSNs - increased cytochrome c release, apoptosome formation, and caspase-3 activity. CB2R stimulation by its selective agonist JWH-015 significantly increased the bcl-2/bax ratio, reduced cytochrome c release, delayed atrophy and degeneration, and improved spontaneous functional recovery through ERK1/2 inactivation. These findings implicate the ECS, particularly CB2R, as part of the endogenous neuroprotective response that is triggered after SCI. Thus, CB2R modulation might represent a promising therapeutic target that lacks psychotropic effects and can be used to exploit ECS-based approaches to counteract neuronal degeneration.

  1. Effects of Intermittent Alcohol Exposure on Emotion and Cognition: A Potential Role for the Endogenous Cannabinoid System and Neuroinflammation

    PubMed Central

    Sanchez-Marin, Laura; Pavon, Francisco J.; Decara, Juan; Suarez, Juan; Gavito, Ana; Castilla-Ortega, Estela; Rodriguez de Fonseca, Fernando; Serrano, Antonia

    2017-01-01

    Intermittent alcohol exposure is a common pattern of adolescent alcohol use that can lead to binge drinking episodes. Alcohol use is known to modulate the endocannabinoid system (ECS), which is involved in neuronal communication, neuroplasticity, neuroinflammation and behavior. Adolescent male Wistar rats were exposed to 4-week intermittent alcohol intoxication (3 g/kg injections for 4 days/week) or saline (N = 12 per group). After alcohol deprivation, adult rats were assessed for emotionality and cognition and the gene expression of the ECS and other factors related to behavior and neuroinflammation was examined in the brain. Alcohol-exposed rats exhibited anxiogenic-like responses and impaired recognition memory but no motor alterations. There were brain region-dependent changes in the mRNA levels of the ECS and molecular signals compared with control rats. Thus, overall, alcohol-exposed rats expressed higher mRNA levels of endocannabinoid synthetic enzymes (N-acyl-phosphatidylethanolamine phospholipase D and diacylglycerol lipases) in the medial-prefrontal cortex (mPFC) but lower mRNA levels in the amygdala. Furthermore, we observed lower mRNA levels of receptors CB1 CB2 and peroxisome proliferator-activated receptor-α in the striatum. Regarding neuropeptide signaling, alcohol-exposed rats displayed lower mRNA levels of the neuropeptide Y signaling, particularly NPY receptor-2, in the amygdala and hippocampus and higher mRNA levels of corticotropin-releasing factor in the hippocampus. Additionally, we observed changes of several neuroinflammation-related factors. Whereas, the mRNA levels of toll-like receptor-4, tumor necrosis factor-α, cyclooxygenase-2 and glial fibrillary acidic protein were significantly increased in the mPFC, the mRNA levels of cyclooxygenase-2 and glial fibrillary acidic protein were decreased in the striatum and hippocampus. However, nuclear factor-κβ mRNA levels were lower in the mPFC and striatum and allograft inflammatory factor-1

  2. Effects of Intermittent Alcohol Exposure on Emotion and Cognition: A Potential Role for the Endogenous Cannabinoid System and Neuroinflammation.

    PubMed

    Sanchez-Marin, Laura; Pavon, Francisco J; Decara, Juan; Suarez, Juan; Gavito, Ana; Castilla-Ortega, Estela; Rodriguez de Fonseca, Fernando; Serrano, Antonia

    2017-01-01

    Intermittent alcohol exposure is a common pattern of adolescent alcohol use that can lead to binge drinking episodes. Alcohol use is known to modulate the endocannabinoid system (ECS), which is involved in neuronal communication, neuroplasticity, neuroinflammation and behavior. Adolescent male Wistar rats were exposed to 4-week intermittent alcohol intoxication (3 g/kg injections for 4 days/week) or saline (N = 12 per group). After alcohol deprivation, adult rats were assessed for emotionality and cognition and the gene expression of the ECS and other factors related to behavior and neuroinflammation was examined in the brain. Alcohol-exposed rats exhibited anxiogenic-like responses and impaired recognition memory but no motor alterations. There were brain region-dependent changes in the mRNA levels of the ECS and molecular signals compared with control rats. Thus, overall, alcohol-exposed rats expressed higher mRNA levels of endocannabinoid synthetic enzymes (N-acyl-phosphatidylethanolamine phospholipase D and diacylglycerol lipases) in the medial-prefrontal cortex (mPFC) but lower mRNA levels in the amygdala. Furthermore, we observed lower mRNA levels of receptors CB1 CB2 and peroxisome proliferator-activated receptor-α in the striatum. Regarding neuropeptide signaling, alcohol-exposed rats displayed lower mRNA levels of the neuropeptide Y signaling, particularly NPY receptor-2, in the amygdala and hippocampus and higher mRNA levels of corticotropin-releasing factor in the hippocampus. Additionally, we observed changes of several neuroinflammation-related factors. Whereas, the mRNA levels of toll-like receptor-4, tumor necrosis factor-α, cyclooxygenase-2 and glial fibrillary acidic protein were significantly increased in the mPFC, the mRNA levels of cyclooxygenase-2 and glial fibrillary acidic protein were decreased in the striatum and hippocampus. However, nuclear factor-κβ mRNA levels were lower in the mPFC and striatum and allograft inflammatory factor-1

  3. Cannabinoid drugs and enhancement of endocannabinoid responses: strategies for a wide array of disease states.

    PubMed

    Karanian, David A; Bahr, Ben A

    2006-09-01

    The endogenous cannabinoid system has revealed potential avenues to treat many disease states. Medicinal indications of cannabinoid drugs including compounds that result in enhanced endocannabinoid responses (EER) have expanded markedly in recent years. The wide range of indications covers chemotherapy complications, tumor growth, addiction, pain, multiple sclerosis, glaucoma, inflammation, eating disorders, age-related neurodegenerative disorders, as well as epileptic seizures, traumatic brain injury, cerebral ischemia, and other excitotoxic insults. Indeed, a great effort has led to the discovery of agents that selectively activate the cannabinoid system or that enhance the endogenous pathways of cannabinergic signaling. The endocannabinoid system is comprised of three primary components: (i) cannabinoid receptors, (ii) endocannabinoid